JP7459922B2 - Vapor chambers, electronic devices and metal sheets for vapor chambers - Google Patents

Description

The present invention relates to a vapor chamber having a sealed space in which a working fluid is sealed, an electronic device, a metal sheet for a vapor chamber, and a method for manufacturing a vapor chamber.

Devices that generate heat, such as central processing units (CPUs), light-emitting diodes (LEDs), and power semiconductors used in mobile devices such as mobile terminals and tablet terminals, are cooled by heat dissipation members such as heat pipes (see, for example, Patent Documents 1 to 5). In recent years, there has been a demand for thinner heat dissipation members in order to make mobile terminals thinner, and vapor chambers that can be made thinner than heat pipes have been developed. A working fluid is sealed inside the vapor chamber, and this working fluid absorbs the heat of the device and releases it to the outside, thereby cooling the device.

More specifically, the working fluid in the vapor chamber receives heat from the device in the part close to the device (evaporation part) and evaporates into vapor, and the vapor then moves to a position away from the evaporation part where it is cooled and condenses into liquid. A liquid flow path part with a capillary structure (wick) is provided in the vapor chamber, and the liquefied working fluid passes through this liquid flow path part and is transported toward the evaporation part, where it receives heat again and evaporates. In this way, the working fluid circulates through the vapor chamber while repeatedly changing phases, i.e., evaporating and condensing, thereby transferring heat from the device and increasing heat dissipation efficiency.

By the way, the liquid flow path section has a plurality of grooves extending in the first direction. The working fluid receives a driving force toward the evaporation section through capillary action, and passes through the groove toward the evaporation section. In addition, another groove extending in a second direction orthogonal to the first direction is provided to allow hydraulic fluid to flow between adjacent grooves. In this manner, a plurality of grooves are formed in a lattice pattern in the liquid flow path, so that the working fluid is distributed evenly within the liquid flow path.

JP 2015-59693 Publication JP2015-88882A JP 2016-17702 A JP 2016-50682 A Japanese Patent Application Publication No. 2016-205693

However, when forming a plurality of grooves in a lattice pattern, problems may arise due to pressure from the outside air.

That is, the vapor chamber is constituted by two metal sheets, and the above-mentioned grooves are formed in at least one of the metal sheets. As a result, the thickness of the metal material is reduced in the portion of the metal sheet where the grooves are formed. Since the space within the liquid flow path section is under reduced pressure, the metal sheet receives pressure from the outside air that causes it to dent inward. For this reason, the metal sheet may dent inward along the groove. In particular, when the vapor chamber is made thinner as described above, the thickness of the metal sheet becomes smaller, which may make it more likely to dent.

When the metal sheet is recessed along the groove extending in the second direction at the intersection where the grooves perpendicular to each other intersect, the recess may be formed to cross the groove extending in the first direction. In this case, the flow path cross-sectional area of the groove along the first direction becomes small, and the flow path resistance of the hydraulic fluid may increase. For this reason, the function of transporting the liquid working fluid to the evaporator may be reduced, and the amount of working fluid supplied to the evaporator may be reduced. In this case, a problem arises in that the amount of heat transported from the evaporator is reduced and the heat transport efficiency is reduced.

The present invention has been made in consideration of these points, and it is possible to improve the transport function of liquid working fluid by ensuring a flow passage cross-sectional area of the liquid flow passage portion, and to improve heat transport efficiency. The present invention aims to provide a vapor chamber, an electronic device, a metal sheet for a vapor chamber, and a method for manufacturing a vapor chamber.

The present invention
A vapor chamber filled with hydraulic fluid,
a first metal sheet;
a second metal sheet provided on the first metal sheet;
a sealed space provided between the first metal sheet and the second metal sheet, a vapor flow path section through which vapor of the working fluid passes, and a liquid flow path section through which the liquid working fluid passes; a sealed space having;
The liquid flow path portion is provided on a surface of the first metal sheet on the second metal sheet side,
The liquid flow path portion has a first mainstream groove, a second mainstream groove, and a third mainstream groove, each of which extends in a first direction and through which the liquid working fluid passes;
The first mainstream groove, the second mainstream groove, and the third mainstream groove are arranged in this order in a second direction perpendicular to the first direction,
A first protrusion row including a plurality of first protrusions arranged in the first direction via a first communication groove is provided between the first main flow groove and the second main flow groove,
A second protrusion row including a plurality of second protrusions arranged in the first direction via a second communication groove is provided between the second main flow groove and the third main flow groove,
The first communication groove communicates the first mainstream groove and the second mainstream groove,
The second communication groove communicates the second mainstream groove with the third mainstream groove,
The second main flow groove includes a first intersection portion where at least a portion of the first communication groove faces the second convex portion, and a first intersection portion where at least a portion of the second communication groove faces the first convex portion. a vapor chamber comprising: two intersections;
I will provide a.

In addition, in the vapor chamber mentioned above,
the first intersection and the second intersection of the second mainstream groove are adjacent to each other;
You can do it like this.

Moreover, in the vapor chamber mentioned above,
The second mainstream groove includes a plurality of the first intersections and a plurality of the second intersections,
The first intersection portions and the second intersection portions of the second mainstream groove are alternately arranged;
You can do it like this.

In addition, in the vapor chamber described above,
the liquid flow path portion further includes a fourth main groove extending in the first direction and through which the liquid working fluid passes,
the fourth mainstream groove is disposed on an opposite side to the second mainstream groove with respect to the third mainstream groove,
a third convex portion row including a plurality of third convex portions arranged in the first direction via a third connecting groove is provided between the third main groove and the fourth main groove,
the third communication groove communicates the third main groove with the fourth main groove,
the third main groove includes a first intersection portion where at least a portion of the second communication groove faces the third convex portion, and a second intersection portion where at least a portion of the third communication groove faces the second convex portion.
This may be done.

Moreover, in the vapor chamber mentioned above,
The first intersection and the second intersection of the third mainstream groove are adjacent to each other,
You can do it like this.

Moreover, in the vapor chamber mentioned above,
The third mainstream groove includes a plurality of the first intersections and a plurality of the second intersections,
The first intersecting portions and the second intersecting portions of the third mainstream groove are alternately arranged;
You can do it like this.

In addition, in the vapor chamber described above,
the second metal sheet has a flat abutment surface that abuts against a surface of the first metal sheet on the second metal sheet side and covers the second main groove,
This may be done.

Moreover, in the vapor chamber mentioned above,
The width of the second mainstream groove is larger than the width of the first convex portion and the width of the second convex portion.
You can do it like this.

Moreover, in the vapor chamber mentioned above,
The width of the first communication groove is larger than the width of the first main flow groove and the width of the second main flow groove, and the width of the second communication groove is larger than the width of the second main flow groove and the third main flow groove. It may be larger than the width of .

Moreover, in the vapor chamber mentioned above,
The depth of the first communication groove is deeper than the depth of the first mainstream groove and the depth of the second mainstream groove,
The depth of the second communication groove is deeper than the depth of the second mainstream groove and the depth of the third mainstream groove,
You can do it like this.

Moreover, in the vapor chamber mentioned above,
The depth of the first intersecting portion and the depth of the second intersecting portion of the second mainstream groove are determined by the depth between the first convex portion and the second convex portion that are adjacent to each other in the second mainstream groove. deeper than the depth of the part,
You can do it like this.

Moreover, in the vapor chamber mentioned above,
The depth of the first intersection and the second intersection of the second mainstream groove are deeper than the first communication groove and the second communication groove,
You can do it like this.

In addition, in the vapor chamber described above,
the first protrusion includes a pair of first protrusion end portions provided at both ends in the first direction, and a first protrusion intermediate portion provided between the pair of first protrusion end portions,
The width of the first protrusion middle portion is smaller than the width of the first protrusion end portion.
This may be done.

In addition, in the vapor chamber described above,
The first protrusion has a rounded corner.
This may be done.

In addition, in the vapor chamber described above,
the second metal sheet has a plurality of main groove convex portions protruding from a surface of the second metal sheet facing the first metal sheet into the first main groove, the second main groove, and the third main groove of the first metal sheet, respectively.
This may be done.

In addition, in the vapor chamber described above,
The cross section of the main groove convex portion is formed in a curved shape.
This may be done.

Moreover, in the vapor chamber mentioned above,
The second metal sheet has a plurality of communication groove protrusions that protrude from a surface of the second metal sheet on the side of the first metal sheet to the first communication groove and the second communication groove of the first metal sheet, respectively. has a section,
You can do it like this.

Moreover, in the vapor chamber mentioned above,
A cross section of the communicating groove convex portion is formed in a curved shape.
You can do it like this.

The present invention also provides a method for producing a method for manufacturing a semiconductor device comprising the steps of:
Housing and
A device contained within the housing; and
an electronic device comprising: a vapor chamber as described above in thermal contact with the device;
I will provide a.

The present invention also provides a method for producing a method for manufacturing a semiconductor device comprising the steps of:
A metal sheet for a vapor chamber for a vapor chamber having a sealed space including a vapor flow path portion through which a vapor of the working liquid passes and a liquid flow path portion through which the liquid working liquid passes,
The first surface;
A second surface provided on the opposite side to the first surface,
The liquid flow path portion is provided on the first surface,
the liquid flow path portion has a first mainstream groove, a second mainstream groove, and a third mainstream groove, each extending in a first direction and through which the liquid working fluid passes,
the first mainstream groove, the second mainstream groove, and the third mainstream groove are arranged in this order in a second direction perpendicular to the first direction,
a first convex-portion row including a plurality of first convex portions arranged in the first direction via a first connecting groove is provided between the first main groove and the second main groove,
a second convex portion row including a plurality of second convex portions arranged in the first direction via a second connecting groove is provided between the second main groove and the third main groove,
the first communication groove communicates the first main groove and the second main groove,
the second communication groove communicates the second main groove and the third main groove,
the second main groove includes a first intersection portion where at least a portion of the first communication groove faces the second convex portion, and a second intersection portion where at least a portion of the second communication groove faces the first convex portion;
I will provide a.

The present invention also provides a method for producing a method for manufacturing a semiconductor device comprising the steps of:
A method for manufacturing a vapor chamber having a sealed space provided between a first metal sheet and a second metal sheet, in which a working fluid is sealed, the sealed space including a vapor flow path portion through which vapor of the working fluid passes and a liquid flow path portion through which the working fluid in a liquid state passes,
a half-etching step of forming the liquid flow path portion on a surface of the first metal sheet on the side of the second metal sheet by half-etching;
a joining step of joining the first metal sheet and the second metal sheet, the joining step forming the sealed space between the first metal sheet and the second metal sheet;
and a sealing step of sealing the hydraulic fluid in the sealed space,
the liquid flow path portion has a first mainstream groove, a second mainstream groove, and a third mainstream groove, each extending in a first direction and through which the liquid working fluid passes,
the first mainstream groove, the second mainstream groove, and the third mainstream groove are arranged in this order in a second direction perpendicular to the first direction,
a first convex-portion row including a plurality of first convex portions arranged in the first direction via a first connecting groove is provided between the first main groove and the second main groove,
a second convex portion row including a plurality of second convex portions arranged in the first direction via a second connecting groove is provided between the second main groove and the third main groove,
the first communication groove communicates the first main groove and the second main groove,
the second communication groove communicates the second main groove and the third main groove,
a second main groove including a first intersection portion where at least a portion of the first communication groove faces the second convex portion, and a second intersection portion where at least a portion of the second communication groove faces the first convex portion;
I will provide a.

According to the present invention, the cross-sectional area of the liquid flow path section can be secured, improving the transport function of the liquid working fluid and improving the heat transport efficiency.

FIG. 1 is a schematic perspective view illustrating an electronic device according to a first embodiment of the present invention. FIG. 2 is a top view showing a vapor chamber according to a first embodiment of the present invention. FIG. 3 is a cross-sectional view of the vapor chamber taken along line AA of FIG. FIG. 4 is a top view of the lower metal sheet of FIG. FIG. 5 is a bottom view of the upper metal sheet of FIG. FIG. 6 is an enlarged top view showing the liquid flow path portion of FIG. FIG. 7 is a cross-sectional view showing the cross section taken along line BB of FIG. 6, with the upper flow passage wall of the upper metal sheet being added thereto. FIG. 8 is a diagram for explaining the step of preparing the lower metal sheet in the vapor chamber manufacturing method according to the first embodiment of the present invention. FIG. 9 is a diagram for explaining the first half-etching step of the lower metal sheet in the vapor chamber manufacturing method according to the first embodiment of the present invention. FIG. 10 is a diagram for explaining a second half-etching step of the lower metal sheet in the manufacturing method of the vapor chamber according to the first embodiment of the present invention. FIG. 11 is a diagram for explaining a temporary fixing step in the vapor chamber manufacturing method according to the first embodiment of the present invention. FIG. 12 is a diagram for explaining a permanent joining step in the manufacturing method of the vapor chamber according to the first embodiment of the present invention. FIG. 13 is a diagram for explaining the step of sealing in the working liquid in the manufacturing method of the vapor chamber according to the first embodiment of the present invention. FIG. 14 is a diagram showing a modification of FIG. 6. FIG. 15 is a top view showing a modification of the liquid flow path convex portion shown in FIG. FIG. 16 is a top view showing another modified example of the liquid flow path convex portion shown in FIG. FIG. 17 is a diagram showing another modification of FIG. 6. FIG. 18 is a diagram showing another modification of FIG. 3. FIG. 19 is an enlarged top view showing the liquid flow path section in the vapor chamber according to the second embodiment of the present invention. FIG. 20 is a cross-sectional view showing the cross section taken along line CC of FIG. 19, with the upper flow passage wall of the upper metal sheet being added. FIG. 21 is a cross-sectional view showing the upper flow path wall portion of the upper metal sheet added to the cross-section taken along the line DD in FIG. 19. FIG. 22 is a cross-sectional view showing the cross section taken along the line E--E of FIG. 19, with the upper flow passage wall of the upper metal sheet added. FIG. 23 is an enlarged sectional view showing the main groove convex portion in the vapor chamber according to the third embodiment of the present invention, and is a view corresponding to FIG. 20. FIG. 24 is an enlarged sectional view showing the connecting groove convex portion in the vapor chamber according to the third embodiment of the present invention, and is a view corresponding to FIG. 21. FIG. 25 is an enlarged sectional view showing the connecting groove convex portion in the vapor chamber according to the third embodiment of the present invention, and is a view corresponding to FIG. 22.

The following describes an embodiment of the present invention with reference to the drawings. Note that in the drawings attached to this specification, the scale and aspect ratios have been appropriately altered and exaggerated from those of the actual objects for the sake of ease of illustration and understanding.

(First embodiment)
A vapor chamber, an electronic device, a metal sheet for a vapor chamber, and a method for manufacturing a vapor chamber according to a first embodiment of the present invention will be described with reference to FIGS. 1 to 18. The vapor chamber 1 in this embodiment is a device installed in the electronic device E in order to cool a device D as a heating element housed in the electronic device E. Examples of device D include electronic devices that generate heat (cooled devices) such as central processing units (CPUs), light emitting diodes (LEDs), and power transistors used in mobile terminals such as mobile terminals and tablet terminals. It will be done.

Here, first, the electronic device E equipped with the vapor chamber 1 according to the present embodiment will be described using a tablet terminal as an example. As shown in FIG. 1, the electronic device E (tablet terminal) includes a housing H, a device D housed in the housing H, and a vapor chamber 1. In the electronic device E shown in FIG. 1, a touch panel display TD is provided on the front surface of the housing H. The vapor chamber 1 is housed in the housing H and arranged so as to be in thermal contact with the device D. This allows the vapor chamber 1 to receive heat generated in the device D when the electronic device E is in use. The heat received by the vapor chamber 1 is released to the outside of the vapor chamber 1 via the working liquid 2 described later. In this way, the device D is effectively cooled. When the electronic device E is a tablet terminal, the device D corresponds to a central processing unit or the like.

Next, the vapor chamber 1 according to this embodiment will be described. The vapor chamber 1 has a sealed space 3 in which a working liquid 2 is sealed, and the working liquid 2 in the sealed space 3 repeatedly changes phase, thereby effectively cooling the device D of the electronic device E described above.

The vapor chamber 1 is generally formed into a thin flat plate shape. Although the planar shape of the vapor chamber 1 is arbitrary, it may be rectangular as shown in FIG. In this case, the vapor chamber 1 has four straight outer edges 1a, 1b forming an out-of-plane contour. Two of the outer edges 1a are formed along a first direction X, which will be described later, and the remaining two outer edges 1b are formed along a second direction Y, which will be described later. The planar shape of the vapor chamber 1 may be, for example, a rectangle with one side of 1 cm and the other side of 3 cm, or a square with one side of 15 cm, and the planar dimensions of the vapor chamber 1 are arbitrary. .

2 and 3, the vapor chamber 1 includes a lower metal sheet 10 (first metal sheet) having an upper surface 10a (first surface) and a lower surface 10b (second surface) provided on the opposite side of the upper surface 10a, and an upper metal sheet 20 (second metal sheet) provided on the lower metal sheet 10. The lower metal sheet 10 and the upper metal sheet 20 each correspond to a metal sheet for a vapor chamber. The upper metal sheet 20 has a lower surface 20a (the surface on the lower metal sheet 10 side) superimposed on the upper surface 10a (the surface on the upper metal sheet 20 side) of the lower metal sheet 10, and an upper surface 20b provided on the opposite side of the lower surface 20a. A device D, which is an object to be cooled, is attached to the lower surface 10b of the lower metal sheet 10 (particularly the lower surface of the evaporation section 11 described later).

The thickness of the vapor chamber 1 is, for example, 0.1 mm to 1.0 mm. Although FIG. 3 shows a case where the thickness T1 of the lower metal sheet 10 and the thickness T2 of the upper metal sheet 20 are equal, the invention is not limited to this, and the thickness T1 of the lower metal sheet 10 and the thickness T2 of the upper metal sheet The thicknesses T2 of the metal sheets 20 do not have to be equal.

Between the lower metal sheet 10 and the upper metal sheet 20, a sealed space 3 is formed in which the working fluid 2 is sealed. In this embodiment, the sealed space 3 has a vapor flow path portion (a lower vapor flow path recess 12 and an upper vapor flow path recess 21 described later) through which the vapor of the working fluid 2 mainly passes, and a liquid flow path portion 30 through which the liquid working fluid 2 mainly passes. Examples of the working fluid 2 include pure water, ethanol, methanol, acetone, etc.

The lower metal sheet 10 and the upper metal sheet 20 are joined by diffusion bonding, which will be described later. In the embodiment shown in FIG. 2 and FIG. 3, the lower metal sheet 10 and the upper metal sheet 20 are both formed in a rectangular shape in a plan view, but this is not limited to this. Here, a plan view refers to a state in which the vapor chamber 1 is viewed from a direction perpendicular to the surface that receives heat from the device D (the lower surface 10b of the lower metal sheet 10) and the surface that releases the received heat (the upper surface 20b of the upper metal sheet 20), and corresponds to, for example, a state in which the vapor chamber 1 is viewed from above (see FIG. 2) or from below.

When the vapor chamber 1 is installed inside a mobile terminal, the vertical relationship between the lower metal sheet 10 and the upper metal sheet 20 may be lost depending on the attitude of the mobile terminal. However, in this embodiment, for convenience, the metal sheet that receives heat from the device D is referred to as the lower metal sheet 10, and the metal sheet that dissipates the received heat is referred to as the upper metal sheet 20, and the description will be given with the lower metal sheet 10 arranged on the lower side and the upper metal sheet 20 arranged on the upper side.

As shown in FIG. 4, the lower metal sheet 10 has an evaporation section 11 where the working fluid 2 evaporates to generate steam, and a lower steam flow path recess 12 (first steam flow path recess) that is provided on the upper surface 10a and has a rectangular shape in a plan view. Of these, the lower steam flow path recess 12 constitutes a part of the above-mentioned sealed space 3, and is configured mainly to allow the steam generated in the evaporation section 11 to pass through.

The evaporator 11 is arranged within the lower vapor flow path recess 12, and the vapor in the lower vapor flow path recess 12 is diffused in the direction away from the evaporator 11, and most of the vapor is relatively small. It is transported towards the cooler periphery. The evaporation section 11 is a section where the working fluid 2 in the sealed space 3 evaporates by receiving heat from the device D attached to the lower surface 10b of the lower metal sheet 10. For this reason, the term evaporation section 11 is not limited to a portion that overlaps the device D, but is used as a concept that includes a portion where the working fluid 2 can be evaporated even if it does not overlap the device D. Here, the evaporator 11 can be provided at any location on the lower metal sheet 10, but in FIGS. 2 and 4, an example is shown in which it is provided in the center of the lower metal sheet 10. . In this case, the operation of the vapor chamber 1 can be stabilized regardless of the posture of the mobile terminal on which the vapor chamber 1 is installed.

In this embodiment, as shown in FIG. 3 and FIG. A plurality of lower flow path wall portions 13 (first flow path wall portions) are provided that protrude in a direction perpendicular to . In this embodiment, an example is shown in which the lower flow path wall portion 13 extends in an elongated shape along the first direction X (longitudinal direction, left-right direction in FIG. 4) of the vapor chamber 1. The lower channel wall 13 includes an upper surface 13a (first contact surface, protruding end surface) that abuts a lower surface 22a of the upper channel wall 22, which will be described later. This upper surface 13a is a surface that will not be etched in the two etching steps described below, and is formed on the same plane as the upper surface 10a of the lower metal sheet 10. Further, the lower flow path wall portions 13 are arranged parallel to each other and spaced apart from each other at equal intervals. In this way, the vapor of the working fluid 2 flows around each lower flow path wall portion 13 and is configured to be transported toward the peripheral edge of the lower steam flow path recess 12, This prevents the flow of steam from being obstructed. Further, the lower channel wall portion 13 is arranged so as to overlap the corresponding upper channel wall portion 22 (described later) of the upper metal sheet 20 in plan view, and is designed to improve the mechanical strength of the vapor chamber 1. ing. The width w0 of the lower channel wall portion 13 is, for example, 0.1 mm to 30 mm, preferably 0.1 mm to 2.0 mm, and the interval d between adjacent lower channel wall portions 13 is 0.1 mm to 30 mm, preferably 0.1 mm to 2.0 mm. It is 1 mm to 30 mm, preferably 0.1 mm to 2.0 mm. Here, the width w0 means the dimension of the lower flow path wall portion 13 in the second direction Y perpendicular to the first direction X, and for example, in the vertical direction in FIG. Corresponds to the dimensions. Further, the height of the lower flow path wall portion 13 (in other words, the depth of the lower steam flow path recess 12) h0 (see FIG. 3) is 10 μm or more than the thickness T1 of the lower metal sheet 10, which will be described later. Preferably small. In this case, the difference between the thickness T1 and the height h0, that is, the thickness of the metal material of the lower metal sheet 10 in the portion where the lower steam flow path recess 12 is formed, can be set to 10 μm or more. Therefore, the strength of the portion can be ensured, and it is possible to prevent the portion from deforming inwardly in response to pressure from the outside air. Such height h0 may be 10 μm to 300 μm. For example, when the thickness T0 of the vapor chamber 1 is 0.5 mm and the thickness T1 of the lower metal sheet 10 and the thickness T2 of the upper metal sheet 20 are equal, the height h0 can be 200 μm.

As shown in Figures 3 and 4, a lower peripheral wall 14 is provided on the peripheral portion of the lower metal sheet 10. The lower peripheral wall 14 is formed to surround the sealed space 3, particularly the lower steam flow path recess 12, and defines the sealed space 3. In addition, lower alignment holes 15 are provided at the four corners of the lower peripheral wall 14 in a plan view to position the lower metal sheet 10 and the upper metal sheet 20.

In this embodiment, the upper metal sheet 20 has substantially the same structure as the lower metal sheet 10, except that a liquid flow path section 30, which will be described later, is not provided. Below, the structure of the upper metal sheet 20 will be explained in more detail.

3 and 5, the upper metal sheet 20 has an upper steam flow path recess 21 (second steam flow path recess) provided on the lower surface 20a. This upper steam flow path recess 21 constitutes a part of the sealed space 3, and is mainly configured to diffuse and cool the steam generated in the evaporation section 11. More specifically, the steam in the upper steam flow path recess 21 diffuses in a direction away from the evaporation section 11, and most of the steam is transported toward the peripheral portion where the temperature is relatively low. Also, as shown in FIG. 3, a housing member Ha constituting a part of the housing H (see FIG. 1) of a mobile terminal or the like is arranged on the upper surface 20b of the upper metal sheet 20. As a result, the steam in the upper steam flow path recess 21 is cooled by the outside via the upper metal sheet 20 and the housing member Ha.

In this embodiment, as shown in Figs. 2, 3 and 5, a plurality of upper flow path walls 22 (second flow path walls) protruding downward (perpendicular to the bottom surface 21a) from the bottom surface 21a of the upper steam flow path recess 21 of the upper metal sheet 20 are provided in the upper steam flow path recess 21. In this embodiment, an example is shown in which the upper flow path wall 22 extends in an elongated shape along the first direction X (left-right direction in Fig. 5) of the vapor chamber 1. The upper flow path wall 22 includes a flat lower surface 22a (second abutment surface, protruding end surface) that abuts against the upper surface 10a of the lower metal sheet 10 (more specifically, the upper surface 13a of the above-mentioned lower flow path wall 13) and covers the liquid flow path portion 30. In addition, the upper flow path walls 22 are arranged parallel to each other at equal intervals. In this way, the vapor of the working fluid 2 flows around each upper flow passage wall 22, and the vapor is transported toward the periphery of the upper steam flow passage recess 21, preventing the flow of the vapor from being impeded. The upper flow passage wall 22 is arranged so as to overlap the corresponding lower flow passage wall 13 of the lower metal sheet 10 in a plan view, improving the mechanical strength of the vapor chamber 1. It is preferable that the width and height of the upper flow passage wall 22 are the same as the width w0 and height h0 of the lower flow passage wall 13 described above. Here, the bottom surface 21a of the upper steam flow passage recess 21 can be called a ceiling surface in the vertical arrangement relationship between the lower metal sheet 10 and the upper metal sheet 20 as shown in FIG. 3, etc., but since it corresponds to the back surface of the upper steam flow passage recess 21, it is referred to as the bottom surface 21a in this specification.

As shown in FIGS. 3 and 5, an upper peripheral wall 23 is provided at the peripheral edge of the upper metal sheet 20. As shown in FIGS. The upper peripheral wall 23 is formed to surround the sealed space 3 , particularly the upper steam passage recess 21 , and defines the sealed space 3 . Furthermore, upper alignment holes 24 for positioning the lower metal sheet 10 and the upper metal sheet 20 are provided at each of the four corners of the upper peripheral wall 23 in a plan view. That is, each upper alignment hole 24 is arranged so as to overlap each of the lower alignment holes 15 described above during temporary fixing, which will be described later, and is configured to enable positioning of the lower metal sheet 10 and the upper metal sheet 20. .

Such lower metal sheet 10 and upper metal sheet 20 are permanently joined to each other, preferably by diffusion bonding. More specifically, as shown in FIG. 3, the upper surface 14a of the lower peripheral wall 14 of the lower metal sheet 10 and the lower surface 23a of the upper peripheral wall 23 of the upper metal sheet 20 abut, and the lower peripheral wall 14 and the upper peripheral wall 23 are joined to each other. As a result, a sealed space 3 in which the working fluid 2 is sealed is formed between the lower metal sheet 10 and the upper metal sheet 20. Further, the upper surface 13a of the lower channel wall portion 13 of the lower metal sheet 10 and the lower surface 22a of the upper channel wall portion 22 of the upper metal sheet 20 are in contact with each other, and correspond to each lower channel wall portion 13. The upper channel wall portions 22 are joined to each other. This improves the mechanical strength of the vapor chamber 1. In particular, since the lower flow path wall portion 13 and the upper flow path wall portion 22 according to the present embodiment are arranged at equal intervals, the mechanical strength at each position of the vapor chamber 1 can be equalized. Note that the lower metal sheet 10 and the upper metal sheet 20 may be joined by other methods such as brazing, instead of diffusion bonding, as long as they can be permanently joined.

2, the vapor chamber 1 further includes an injection section 4 at one end of a pair of ends in the first direction X for injecting the working fluid 2 into the sealed space 3. The injection section 4 has a lower injection protrusion 16 protruding from the end face of the lower metal sheet 10 and an upper injection protrusion 25 protruding from the end face of the upper metal sheet 20. A lower injection flow path recess 17 is formed on the upper surface of the lower injection protrusion 16, and an upper injection flow path recess 26 is formed on the lower surface of the upper injection protrusion 25. The lower injection flow path recess 17 is connected to the lower steam flow path recess 12, and the upper injection flow path recess 26 is connected to the upper steam flow path recess 21. The lower injection flow path recess 17 and the upper injection flow path recess 26 form an injection flow path for the working fluid 2 when the lower metal sheet 10 and the upper metal sheet 20 are joined. The working fluid 2 is injected into the sealed space 3 through the injection flow path. In this embodiment, the injection part 4 is shown as being provided at one of a pair of ends of the vapor chamber 1 in the first direction X, but is not limited to this.

Next, the liquid flow path portion 30 of the lower metal sheet 10 will be described in more detail using Figures 3, 4, 6 and 7.

As shown in FIGS. 3 and 4, a liquid flow path portion through which the liquid working fluid 2 passes is provided on the upper surface 10a of the lower metal sheet 10 (more specifically, the upper surface 13a of each lower flow path wall portion 13). 30 are provided. The liquid flow path section 30 constitutes a part of the sealed space 3 described above, and communicates with the lower steam flow path recess 12 and the upper steam flow path recess 21 described above.

As shown in FIG. 6, the liquid flow path section 30 has a first mainstream groove 31, a second mainstream groove 32, a third mainstream groove 33, and a fourth mainstream groove 34. The first to fourth mainstream grooves 31 to 34 each extend linearly in the first direction X to allow the liquid working fluid 2 to pass through, and are arranged in this order in the second direction Y described above. In other words, the fourth mainstream groove 34 is arranged on the opposite side of the third mainstream groove 33 from the second mainstream groove 32. The first to fourth mainstream grooves 31 to 34 are mainly configured to transport the working fluid 2 condensed from the steam generated in the evaporation section 11 toward the evaporation section 11.

A first convex row 41 is provided between the first mainstream groove 31 and the second mainstream groove 32. This first convex row 41 includes a plurality of first convex portions 41a arranged in the first direction X. In FIG. 6, each first convex portion 41a is formed in a rectangular shape so that the first direction X is the longitudinal direction in a plan view. A first communication groove 51 is interposed between adjacent first convex portions 41a. The first communication groove 51 is formed to extend in the second direction Y, and communicates with the first mainstream groove 31 and the second mainstream groove 32, so that the working fluid 2 can move between the first mainstream groove 31 and the second mainstream groove 32. The first communication groove 51 is a region between adjacent first convex portions 41a, and is a region between the first mainstream groove 31 and the second mainstream groove 32.

A second convex row 42 is provided between the second main flow groove 32 and the third main flow groove 33 . This second convex row 42 includes a plurality of second convex portions 42a arranged in the first direction X. In FIG. 6, each second convex portion 42a is formed in a rectangular shape so that the first direction X is the longitudinal direction in plan view. A second communication groove 52 is interposed between the second convex portions 42a adjacent to each other. The second communication groove 52 is formed to extend in the second direction Y, communicates the second mainstream groove 32 and the third mainstream groove 33, and is between the second mainstream groove 32 and the third mainstream groove 33. The hydraulic fluid 2 can flow back and forth. The second communication groove 52 is a region between the second convex portions 42a adjacent to each other, and is a region between the second mainstream groove 32 and the third mainstream groove 33.

The second main groove 32 includes a first intersection P1 with which the first connecting groove 51 communicates, and a second intersection P2 with which the second connecting groove 52 communicates.

At the first intersection P1, at least a portion of the first communication groove 51 faces the second convex portion 42a. As shown in FIG. 6, at the first intersection P1, the entire first communication groove 51 (the entire area of the first communication groove 51 in the width direction (first direction X)) faces the second convex portion 42a. There is. As a result, the side wall 36 on the opposite side to the first communication groove 51 (the second A wall of the convex portion 42a) is arranged. In the form shown in FIG. 6, the first communication groove 51 is arranged so as to overlap the center of the second convex portion 42a in the first direction X when viewed in the second direction Y. In this way, the second main flow groove 32 and the first communication groove 51 intersect in a T-shape at the first intersection P1. The first intersection P1 is a region between the main groove main body portions 31a to 34a adjacent to each other in the first direction The area is between . In other words, the main grooves 31 to 34 and the communication grooves 51 to 54 intersect (ie, overlap). Here, the first main flow groove body parts 31a to 34a constitute a part of the first to fourth main flow grooves 31 to 34, and are provided between the first intersection P1 and the second intersection P2. This is a portion located between adjacent convex portions 41a to 44a.

Similarly, at the second intersection P2, at least a part of the second communication groove 52 faces the first convex portion 41a. As shown in FIG. 6, at the second intersection P2, the entire second communication groove 52 (the entire area in the width direction (first direction X) of the second communication groove 52) faces the first convex portion 41a. As a result, the side wall 35 (the wall of the first convex portion 41a) of the pair of side walls 35, 36 of the second mainstream groove 32 along the first direction X on the opposite side to the second communication groove 52 is arranged throughout the second intersection P2. In the embodiment shown in FIG. 6, when viewed in the second direction Y, the second communication groove 52 is arranged so as to overlap the center of the first convex portion 41a in the first direction X. In this way, at the second intersection P2, the second mainstream groove 32 and the second communication groove 52 intersect in a T-shape. The second intersection P2 is the region between the adjacent main groove body portions 31a-34a in the first direction X, and is the region between the adjacent communication grooves 51-54 and the protrusions 41a-44a in the second direction Y. In other words, it is the region where the main grooves 31-34 and the communication grooves 51-54 intersect (i.e., overlap).

As described above, at the first intersection P1 of the second mainstream groove 32, the first communication groove 51 faces the second protrusion 42a, and at the second intersection P2 of the second mainstream groove 32, the first communication groove 51 faces the second convex portion 42a. The two communication grooves 52 face the first protrusion 41a. As a result, the first communication groove 51 and the second communication groove 52 are not arranged in a straight line. That is, the first communication groove 51 communicating with the second mainstream groove 32 on one side and the second communication groove 52 communicating on the other side are not arranged in a straight line.

In this embodiment, the first protrusions 41a and the second protrusions 42a have the same shape, and the arrangement pitch of the first protrusions 41a and the arrangement pitch of the second protrusions 42a are the same. The first convex portion 41a and the second convex portion 42a are arranged offset from each other in the first direction X with a dimension that is half of this arrangement pitch.

Further, in this embodiment, the first intersection P1 and the second intersection P2 of the second mainstream groove 32 are adjacent to each other. That is, no other intersection (for example, a third intersection P3 as shown in FIG. 14, which will be described later) is interposed between the first intersection P1 and the second intersection P2. The second mainstream groove 32 includes a plurality of first intersections P1 and a plurality of second intersections P2, and the first intersections P1 and the second intersections P2 are arranged in the first direction X. arranged alternately. That is, the pair of side walls 35 and 36 of the second mainstream groove 32 are formed intermittently, and the dividing positions of the side walls 35 and 36 are shifted from each other in the first direction X.

By the way, a third convex row 43 is provided between the third main flow groove 33 and the fourth main flow groove 34. The third protrusion row 43 includes a plurality of third protrusions 43a arranged in the first direction X, similarly to the first protrusion row 41. A third communication groove 53 is interposed between the third protrusions 43a adjacent to each other. The third communication groove 53 is formed to extend in the second direction Y, communicates the third mainstream groove 33 and the fourth mainstream groove 34, and is between the third mainstream groove 33 and the fourth mainstream groove 34. The hydraulic fluid 2 can flow back and forth. The third communication groove 53 is a region between the third convex portions 43 a adjacent to each other, and is a region between the third mainstream groove 33 and the fourth mainstream groove 34 .

The third main groove 33 includes a first intersection P1 to which the second communication groove 52 communicates, and a second intersection P2 to which the third communication groove 53 communicates. At the first intersection P1, at least a part of the second communication groove 52 faces the third convex portion 43a. In FIG. 6, at the first intersection P1, the entire second communication groove 52 (the entire area in the width direction (first direction X) of the second communication groove 52) faces the third convex portion 43a. As a result, the side wall 36 (the wall of the third convex portion 43a) of the pair of side walls 35, 36 of the third main groove 33 along the first direction X on the opposite side to the second communication groove 52 exists throughout the first intersection P1. In the embodiment shown in FIG. 6, the second communication groove 52 is arranged to overlap the center of the third convex portion 43a in the first direction X when viewed in the second direction Y. In this way, the third main groove 33 and the second connecting groove 52 intersect in a T-shape at the first intersection P1.

Similarly, at the second intersection P2, at least a portion of the third communication groove 53 faces the second convex portion 42a. In FIG. 6, the entire third communication groove 53 (the entire area of the third communication groove 53 in the width direction (first direction X)) faces the second convex portion 42a at the second intersection P2. As a result, the side wall 35 on the opposite side to the third communication groove 53 (the second A wall of the convex portion 42a) is arranged. In the form shown in FIG. 6, the third communication groove 53 is arranged so as to overlap the center of the second convex portion 42a in the first direction X when viewed in the second direction Y. In this way, the third main flow groove 33 and the third communication groove 53 intersect in a T-shape at the second intersection P2.

That is, in the present embodiment, the first convex portion 41a, the second convex portion 42a, and the third convex portion 43a have the same shape, and the arrangement pitch of the first convex portion 41a and the arrangement pitch of the second convex portion 42a are the same. The arrangement pitch of the third convex portions 43a is the same. The second convex portion 42a and the third convex portion 43a are arranged offset from each other in the first direction X with a dimension that is half of this arrangement pitch. As a result, the first convex portion 41a and the third convex portion 43a are arranged at the same position in the first direction X, and when viewed in the second direction Y, the first convex portion 41a and the third convex portion 43a are overlapping.

In this embodiment, like the second mainstream groove 32, the first intersection P1 and the second intersection P2 of the third mainstream groove 33 are adjacent to each other. The third mainstream groove 33 includes a plurality of first intersections P1 and a plurality of second intersections P2, and the first intersections P1 and the second intersections P2 are arranged in the first direction X. arranged alternately. That is, the pair of side walls 35 and 36 of the third mainstream groove 33 are formed intermittently, and the dividing positions of the side walls 35 and 36 are shifted from each other in the first direction X.

Since the first convex portion 41a, the second convex portion 42a, and the third convex portion 43a are arranged as described above, in this embodiment, the first convex portion 41a, the second convex portion 42a, and the third convex portion The arrangement of 43a is staggered. As a result, the first communication groove 51, the second communication groove 52, and the third communication groove 53 are also arranged in a staggered manner.

In FIG. 6, one set of mainstream grooves is shown, where the first to fourth mainstream grooves 31 to 34 mentioned above are one set. A plurality of these sets may be provided, and a large number of mainstream grooves 31 to 34 as a whole may be formed on the upper surface 13a of the lower channel wall portion 13. Note that the main stream grooves constituting the liquid flow path section 30 do not need to be composed of the first to fourth main stream grooves 31 to 34 as one set, and as long as at least three main stream grooves are formed, the main stream grooves The number is not limited to a multiple of 4 and is arbitrary.

In this case, the above-mentioned first mainstream groove 31 is provided on the opposite side of the fourth mainstream groove 34 from the third mainstream groove 33, and the fourth mainstream groove 34 and the first mainstream groove 31 are connected to each other. A fourth convex row 44 is provided between them. The fourth convex row 44 includes a plurality of fourth convex portions 44a arranged in the first direction X, similar to the second convex row 42 described above. The fourth convex portion 44a and the second convex portion 42a are arranged at the same position in the first direction X, and when viewed in the second direction Y, the fourth convex portion 44a and the second convex portion 42a overlap. There is. A fourth communication groove 54 is interposed between the adjacent fourth convex portions 44a. The fourth communication groove 54 is formed to extend in the second direction Y, communicates the fourth mainstream groove 34 and the first mainstream groove 31, and is between the fourth mainstream groove 34 and the first mainstream groove 31. The hydraulic fluid 2 can flow back and forth. The fourth communication groove 54 is a region between adjacent fourth convex portions 44a, and is a region between the fourth mainstream groove 34 and the first mainstream groove 31.

The fourth main flow groove 34 has a first intersection P1 and a second intersection P2 similar to the second main flow groove 32. Here, the third communication groove 53 communicates with the fourth main groove 34 at the first intersection P1, and the fourth communication groove 54 communicates with the fourth main groove 34 at the second intersection P2. Further, the first mainstream groove 31 has a first intersection P1 and a second intersection P2 similar to the third mainstream groove 33. Here, the fourth communication groove 54 communicates with the first mainstream groove 31 at the first intersection P1, and the first communication groove 51 communicates with the first mainstream groove 31 at the second intersection P2. The first intersection P1 and the second intersection P2 in the first main flow groove 31 and the fourth main flow groove 34 are the same as the first intersection P1 and the second intersection P2 in the second main flow groove 32 and the third main flow groove 33. Therefore, detailed explanation will be omitted here.

Each of the protrusions 41a to 44a may be rectangular and arranged in a staggered pattern across the entirety of each liquid flow path section 30, as described above.

By the way, the width w1 (dimension in the second direction Y) of the first to fourth mainstream grooves 31 to 34 is larger than the width w2 (dimension in the second direction Y) of the first to fourth convex portions 41a to 44a. is suitable. In this case, the proportion of the first to fourth mainstream grooves 31 to 34 in the upper surface 13a of the lower channel wall portion 13 can be increased. Therefore, the flow path density of the mainstream grooves 31 to 34 on the upper surface 13a can be increased, and the transport function of the liquid working fluid 2 can be improved. For example, the width w1 of the first to fourth main grooves 31 to 34 may be 30 μm to 200 μm, and the width w2 of the first to fourth convex portions 41a to 44a may be 20 μm to 180 μm.

It is preferable that the depth h1 of the first to fourth mainstream grooves 31 to 34 is smaller than the depth h0 of the lower steam flow path recess 12 described above. In this case, the capillary action of the first to fourth mainstream grooves 31 to 34 can be enhanced. For example, the depth h1 of the first to fourth mainstream grooves 31 to 34 is preferably about half of h0, and may be 5 μm to 180 μm.

Furthermore, it is preferable that the width w3 (dimension in the first direction X) of the first to fourth communication grooves 51 to 54 is smaller than the width w1 of the first to fourth main flow grooves 31 to 34. In this case, while the liquid working fluid 2 is being transported toward the evaporation section 11 in each of the main flow grooves 31 to 34, it is possible to prevent the working fluid 2 from flowing into the communication grooves 51 to 54, and the transport of the working fluid 2 Functionality can be improved. On the other hand, if dryout occurs in any of the main flow grooves 31 to 34, the hydraulic fluid 2 can be moved from the adjacent main flow grooves 31 to 34 through the corresponding communication grooves 51 to 54, and the dryout occurs. This can be quickly resolved and the transport function of the hydraulic fluid 2 can be ensured. In other words, if the first to fourth communication grooves 51 to 54 can communicate with each other, they can perform their functions even if they are smaller than the width w1 of the main grooves 31 to 34. can. The width w3 of the first to fourth communication grooves 51 to 54 may be, for example, 20 μm to 180 μm.

The depth h3 of the first to fourth communication grooves 51 to 54 may be shallower than the depth h1 of the first to fourth main flow grooves 31 to 34, depending on the width w3 thereof. For example, the depth h3 (not shown) of the first to fourth communication grooves 51 to 54 may be 40 μm when the depth h1 of the first to fourth main flow grooves 31 to 34 is 50 μm.

The method for checking the width and depth of the main grooves 31-34 and the width and depth of the connecting grooves 51-54 from the completed vapor chamber 1 will be described later.

The shape of the cross section (cross section in the second direction Y) of the first to fourth mainstream grooves 31 to 34 is not particularly limited, and may be, for example, rectangular, curved, semicircular, or V-shaped. . The cross-sectional shapes (cross-sections in the first direction X) of the first to fourth communication grooves 51 to 54 are also similar. FIG. 7 shows an example in which the first to fourth mainstream grooves 31 to 34 have rectangular cross sections.

The above-mentioned liquid flow path section 30 is formed on the upper surface 13a of the lower flow path wall section 13 of the lower metal sheet 10. On the other hand, in this embodiment, the lower surface 22a of the upper flow path wall section 22 of the upper metal sheet 20 is formed flat. As a result, each of the main flow grooves 31 to 34 of the liquid flow path section 30 is covered with the flat lower surface 22a. In this case, as shown in FIG. 7, a pair of side walls 35, 36 extending in the first direction X of the main flow grooves 31 to 34 and the lower surface 22a of the upper flow path wall section 22 can form two right-angled or acute-angled corners 37, and the capillary action at these two corners 37 can be enhanced. That is, the two corners 38 can be formed by the bottom surface of the main grooves 31-34 (the surface on the side of the lower surface 10b of the lower metal sheet 10) and the pair of side walls 35, 36 of the main grooves 31-34, but when the main grooves 31-34 are formed by etching as described below, the corners 38 on the bottom surface side tend to be rounded. Therefore, by forming the lower surface 22a of the upper flow passage wall 22 flat so as to cover the main grooves 31-34 and the connecting grooves 51-54, the capillary action can be enhanced at the corners 37 on the side of the lower surface 22a of the upper flow passage wall 22. Note that in FIG. 7, for clarity of the drawing, the side walls 35, 36 and the corners 37, 38 are shown only for the first main groove 31, and the side walls 35, 36 and the corners 37, 38 are omitted for the second to fourth main grooves 32-34.

The material used for the lower metal sheet 10 and the upper metal sheet 20 is not particularly limited as long as it has good thermal conductivity. For example, it is preferable that the lower metal sheet 10 and the upper metal sheet 20 are made of copper (oxygen-free copper) or a copper alloy. This increases the thermal conductivity of the lower metal sheet 10 and the upper metal sheet 20. This increases the heat dissipation efficiency of the vapor chamber 1. Alternatively, other metal materials such as aluminum or other metal alloy materials such as stainless steel can be used for these metal sheets 10 and 20 as long as the desired heat dissipation efficiency can be obtained.

Next, the operation of this embodiment having such a configuration will be explained. Here, first, a method for manufacturing the vapor chamber 1 will be explained using FIGS. 8 to 13, but the explanation of the half-etching process of the upper metal sheet 20 will be simplified. Note that FIGS. 8 to 13 show cross sections similar to the cross-sectional view of FIG. 3.

First, as shown in Figure 8, a flat metal material sheet M is prepared as a preparation step.

Subsequently, as shown in FIG. 9, the metal material sheet M is half-etched to form a lower vapor flow path recess 12 that constitutes a part of the sealed space 3. In this case, first, a first resist film (not shown) is formed on the upper surface Ma of the metal material sheet M in a pattern corresponding to the plurality of lower channel walls 13 and the lower peripheral wall 14 by photolithography technology. . Subsequently, as a first half-etching step, the upper surface Ma of the metal material sheet M is half-etched. As a result, a portion of the upper surface Ma of the metal material sheet M that corresponds to the resist opening (not shown) of the first resist film is half-etched, and the lower vapor flow path recess 12 and the lower portion as shown in FIG. A side channel wall portion 13 and a lower peripheral wall 14 are formed. At this time, the lower injection channel recess 17 shown in FIGS. 2 and 4 is also formed at the same time, and the metal material sheet M is etched from the upper surface Ma and the lower surface so as to have the outer contour shape shown in FIG. , a predetermined external contour shape is obtained. After the first half-etching process, the first resist film is removed. Note that half etching means etching for forming a recess that does not penetrate the material. Therefore, the depth of the recess formed by half etching is not limited to half the thickness of the lower metal sheet 10. As the etching solution, for example, an iron chloride-based etching solution such as a ferric chloride aqueous solution, or a copper chloride-based etching solution such as a copper chloride aqueous solution can be used.

After the lower steam flow path recess 12 is formed, the liquid flow path section 30 is formed on the upper surface 13a of the lower flow path wall section 13, as shown in FIG. 10.

In this case, first, a second resist film (not shown) is formed on the upper surface 13a of the lower flow path wall 13 by photolithography in a pattern corresponding to the first to fourth convex portions 41a to 44a of the liquid flow path portion 30. Then, as a second half-etching step, the upper surface 13a of the lower flow path wall 13 is half-etched. As a result, the portions of the upper surface 13a that correspond to the resist openings (not shown) of the second resist film are half-etched, and the liquid flow path portion 30 is formed on the upper surface 13a of the lower flow path wall 13. That is, the respective convex portions 41a to 44a are formed on the upper surface 13a. The first to fourth main grooves 31 to 34 and the first to fourth connecting grooves 51 to 54 are defined by these convex portions 41a to 44a. After the second half-etching step, the second resist film is removed.

In this way, the lower metal sheet 10 in which the liquid flow path section 30 is formed is obtained. In addition, by forming the liquid flow path part 30 as a second half etching process which is a process different from the first half etching process, the main flow is formed at a depth different from the depth h0 of the lower vapor flow path recessed part 12. It becomes possible to easily form the grooves 31 to 34 and the communication grooves 51 to 54. However, the lower vapor flow path recess 12, the main grooves 31 to 34, and the communication grooves 51 to 54 may be formed in the same half-etching process. In this case, the number of half-etching steps can be reduced, and the manufacturing cost of the vapor chamber 1 can be reduced.

On the other hand, in the same manner as the lower metal sheet 10, the upper metal sheet 20 is half-etched from the lower surface 20a to form the upper vapor passage recess 21, the upper passage wall 22, and the upper peripheral wall 23. In this way, the upper metal sheet 20 described above is obtained.

Next, as shown in FIG. 11, in a temporary fixing step, the lower metal sheet 10 having the lower steam passage recess 12 and the upper metal sheet 20 having the upper steam passage recess 21 are temporarily joined. In this case, first, by using the lower alignment hole 15 (see FIGS. 2 and 4) of the lower metal sheet 10 and the upper alignment hole 24 (see FIGS. 2 and 5) of the upper metal sheet 20, The metal sheet 10 and the upper metal sheet 20 are positioned. Subsequently, the lower metal sheet 10 and the upper metal sheet 20 are fixed. The fixing method is not particularly limited, but for example, the lower metal sheet 10 and the upper metal sheet 20 may be fixed by resistance welding to the lower metal sheet 10 and the upper metal sheet 20. It's okay. In this case, as shown in FIG. 11, it is preferable to perform spot resistance welding using an electrode rod 40. Laser welding may be used instead of resistance welding. Alternatively, the lower metal sheet 10 and the upper metal sheet 20 may be ultrasonically bonded and fixed by irradiating ultrasonic waves. Furthermore, although an adhesive may be used, it is preferable to use an adhesive that does not have an organic component or has a small amount of organic component. In this way, the lower metal sheet 10 and the upper metal sheet 20 are fixed in a positioned state.

After the temporary fixing, as shown in FIG. 12, the lower metal sheet 10 and the upper metal sheet 20 are permanently bonded by diffusion bonding as a permanent bonding process. Diffusion bonding is a method in which the lower metal sheet 10 and the upper metal sheet 20 to be bonded are brought into close contact with each other, and in a controlled atmosphere such as a vacuum or an inert gas, the metal sheets 10 and 20 are pressurized in the direction of contact and heated to bond them by utilizing the diffusion of atoms that occurs at the bonding surface. In diffusion bonding, the materials of the lower metal sheet 10 and the upper metal sheet 20 are heated to a temperature close to the melting point, but since it is lower than the melting point, it is possible to avoid the metal sheets 10 and 20 from melting and deforming. More specifically, the upper surface 14a of the lower peripheral wall 14 of the lower metal sheet 10 and the lower surface 23a of the upper peripheral wall 23 of the upper metal sheet 20 are diffusion bonded as bonding surfaces. As a result, the lower peripheral wall 14 and the upper peripheral wall 23 form a sealed space 3 between the lower metal sheet 10 and the upper metal sheet 20. In addition, the lower injection flow path recess 17 (see Figures 2 and 4) and the upper injection flow path recess 26 (see Figures 2 and 5) form an injection flow path for the working fluid 2 that communicates with the sealed space 3. Furthermore, the upper surface 13a of the lower flow path wall 13 of the lower metal sheet 10 and the lower surface 22a of the upper flow path wall 22 of the upper metal sheet 20 are diffusion bonded to form a joining surface, improving the mechanical strength of the vapor chamber 1. The liquid flow path portion 30 formed on the upper surface 13a of the lower flow path wall 13 remains as a flow path for the liquid working fluid 2.

After the permanent joining, as shown in FIG. 13, the working fluid 2 is injected into the sealed space 3 from the injection section 4 (see FIG. 2) as a sealing process. At this time, the sealed space 3 is first evacuated to reduce the pressure, and then the working fluid 2 is injected into the sealed space 3. During injection, the working fluid 2 passes through the injection flow path formed by the lower injection flow path recess 17 and the upper injection flow path recess 26. For example, the amount of the working fluid 2 to be sealed may be 10% to 30% of the total volume of the sealed space 3, depending on the configuration of the liquid flow path section 30 inside the vapor chamber 1.

After injection of the working fluid 2, the injection channel described above is sealed. For example, the injection portion 4 may be irradiated with a laser to partially melt the injection portion 4 and seal the injection channel. As a result, communication between the sealed space 3 and the outside is cut off, and the hydraulic fluid 2 is sealed in the sealed space 3. In this way, the hydraulic fluid 2 in the sealed space 3 is prevented from leaking to the outside. Note that for sealing, the injection portion 4 may be caulked or brazed.

In the manner described above, the vapor chamber 1 according to this embodiment is obtained.

Next, we will explain how the vapor chamber 1 operates, i.e., how the device D is cooled.

The vapor chamber 1 obtained as described above is installed in a housing H of a mobile terminal or the like, and a device D, such as a CPU, which is an object to be cooled, is attached to the lower surface 10b of the lower metal sheet 10. Since the amount of working fluid 2 injected into the sealed space 3 is small, the liquid working fluid 2 in the sealed space 3 adheres to the wall surfaces of the sealed space 3, i.e., the wall surfaces of the lower steam flow path recess 12, the wall surfaces of the upper steam flow path recess 21, and the wall surfaces of the liquid flow path section 30, due to its surface tension.

When the device D generates heat in this state, the working fluid 2 present in the evaporation section 11 of the lower vapor flow path recess 12 receives heat from the device D. The received heat is absorbed as latent heat, the working fluid 2 evaporates (vaporizes), and vapor of the working fluid 2 is generated. Most of the generated steam diffuses within the lower steam flow path recess 12 and the upper steam flow path recess 21 that constitute the sealed space 3 (see solid line arrows in FIG. 4). The vapor in the upper vapor flow path recess 21 and the lower vapor flow path recess 12 leaves the evaporator 11, and most of the vapor is transported toward the peripheral edge of the vapor chamber 1 where the temperature is relatively low. The diffused vapor radiates heat to the lower metal sheet 10 and the upper metal sheet 20 and is cooled. The heat received by the lower metal sheet 10 and the upper metal sheet 20 from the steam is transferred to the outside via the housing member Ha (see FIG. 3).

The steam condenses by losing the latent heat absorbed in the evaporation section 11 by dissipating heat to the lower metal sheet 10 and the upper metal sheet 20. The condensed liquid working fluid 2 adheres to the wall surface of the lower steam flow path recess 12 or the wall surface of the upper steam flow path recess 21. Here, since the working fluid 2 continues to evaporate in the evaporation section 11, the working fluid 2 in the part of the liquid flow path section 30 other than the evaporation section 11 is transported toward the evaporation section 11 (see the dashed arrow in FIG. 4). As a result, the liquid working fluid 2 adhered to the wall surface of the lower steam flow path recess 12 and the wall surface of the upper steam flow path recess 21 moves toward the liquid flow path section 30 and enters the liquid flow path section 30. That is, the liquid working fluid 2 enters the first to fourth mainstream grooves 31 to 34 through the first to fourth communication grooves 51 to 54, and the liquid working fluid 2 is filled in each mainstream groove 31 to 34 and each communication groove 51 to 54. As a result, the filled working fluid 2 obtains a driving force toward the evaporation section 11 due to the capillary action of each of the main grooves 31 to 34, and is smoothly transported toward the evaporation section 11.

In the liquid flow path section 30, each of the main stream grooves 31 to 34 communicates with other adjacent main stream grooves 31 to 34 via corresponding communication grooves 51 to 54. As a result, the liquid working fluid 2 flows back and forth between the adjacent mainstream grooves 31 to 34, and dryout is suppressed from occurring in the mainstream grooves 31 to 34. Therefore, a capillary action is applied to the working fluid 2 in each of the main flow grooves 31 to 34, and the working fluid 2 is smoothly transported toward the evaporation section 11.

In addition, since each of the main grooves 31-34 includes the first intersection P1 and the second intersection P2 described above, the capillary action acting on the working fluid 2 in each of the main grooves 31-34 is prevented from being lost. Here, for example, if the first communication groove 51 and the second communication groove 52 are arranged in a straight line via the second main groove 32, both of the pair of side walls 35, 36 will not be present at the intersection with the second main groove 32. In this case, the capillary action in the direction toward the evaporation section 11 will be lost at the intersection, and the driving force of the working fluid 2 toward the evaporation section 11 may be reduced.

In contrast, in this embodiment, as described above, the first communication groove 51 that communicates with the second mainstream groove 32 on one side and the second communication groove 52 that communicates with the second mainstream groove 32 on the other side are not arranged in a straight line. In this case, as shown in FIG. 6, at the first intersection P1, the side wall 36 opposite the first communication groove 51 side of the pair of side walls 35, 36 along the first direction X of the second mainstream groove 32 is arranged. This makes it possible to prevent the capillary action in the direction toward the evaporation section 11 from being lost at the first intersection P1. Similarly, at the second intersection P2, the side wall 35 opposite the second communication groove 52 side is arranged, so that the capillary action in the direction toward the evaporation section 11 can be prevented from being lost. Therefore, at each intersection P1, P2, the capillary action can be suppressed from being reduced, and the working fluid 2 heading toward the evaporation section 11 can be continuously given the capillary action.

In the present embodiment, the first intersection portions P1 and the second intersection portions P2 of the second mainstream groove 32 are alternately arranged. That is, at the first intersection P1 of the second mainstream groove 32, the side wall 36 on the side of the second communication groove 52 imparts a capillary action to the hydraulic fluid 2 in the second mainstream groove 32, but at the second intersection P2, The side wall 35 on the side of the first communication groove 51 that is opposite to the side wall 36 can impart capillary action to the working fluid 2 in the second mainstream groove 32 . Therefore, the capillary action acting on the hydraulic fluid 2 in the second mainstream groove 32 can be made equal in the width direction (second direction Y).

In this embodiment, the first main flow groove 31, the third main flow groove 33, and the fourth main flow groove 34 have the same first intersection P1 and second intersection P2 as the second main flow groove 32, respectively. . This makes it possible to suppress the capillary action exerted on the working fluid 2 in the first to fourth mainstream grooves 31 to 34 from being reduced.

The working fluid 2 that has reached the evaporator 11 receives heat from the device D again and evaporates. In this way, the working fluid 2 circulates within the vapor chamber 1 while repeating phase changes, that is, evaporation and condensation, thereby transferring and discharging the heat of the device D. As a result, device D is cooled.

By the way, in this embodiment, as described above, in the second mainstream groove 32, the first communication groove 51 and the second communication groove 52 are not arranged in the same straight line. Therefore, depending on the posture of the mobile terminal in which the vapor chamber 1 is installed, the second direction Y may be along the gravity direction rather than the first direction X. In such a posture, if the first communication groove 51 and the second communication groove 52 are arranged in the same straight line, a part of the hydraulic fluid 2 in each of the main flow grooves 31 to 34 will be affected by gravity. Therefore, it is considered that the hydraulic fluid 2 flows toward one side in the second direction Y in each of the communication grooves 51 to 54, and the hydraulic fluid 2 is biased toward the one side.

However, in the present embodiment, when each of the main grooves 31-34 includes a first intersection P1 and a second intersection P2, the working fluid 2 can be prevented from flowing linearly toward one side of the second direction Y. In other words, the working fluid 2 can proceed toward the evaporation section 11 through the main grooves 31-34 while moving toward one side of the second direction Y, and the flow of the working fluid 2 toward the evaporation section 11 can be prevented from weakening. Therefore, even if the vapor chamber 1 is in a position in which gravity acts in a direction that inhibits the transport function of the working fluid 2, the transport function of the liquid working fluid 2 can be improved.

By the way, the pressure inside the sealed space 3 is reduced as described above. As a result, the lower metal sheet 10 and the upper metal sheet 20 are under pressure from the outside air in the direction of concave inward. Here, when the first communication groove 51 and the second communication groove 52 are arranged in a straight line via the second main flow groove 32, the second main flow groove 32, the first communication groove 51 and the second communication groove 52 An intersection is formed where the two intersect in a cross shape. In this case, the lower metal sheet 10 and the upper metal sheet 20 are recessed inwardly along the groove extending in the second direction Y perpendicular to the first direction X, and the recess crosses the second mainstream groove 32. can be formed. In this case, the flow passage cross-sectional area of the second mainstream groove 32 becomes small, and the flow passage resistance of the working fluid 2 may increase.

In contrast, in the present embodiment, at the first intersection P1 of the second mainstream groove 32, the first communication groove 51 faces the second convex portion 42a. Thereby, even if the lower metal sheet 10 and the upper metal sheet 20 are recessed inward along the first communication groove 51, the recess can be prevented from crossing the second mainstream groove 32. Therefore, the cross-sectional area of the second mainstream groove 32 can be secured, and the flow of the hydraulic fluid 2 can be prevented from being obstructed. For example, in a vapor chamber for a mobile terminal that is required to be thin, it may be difficult to suppress concave deformation due to the thinness. Even when applied to the present invention, according to the present embodiment, concave deformation can be effectively suppressed. For example, if the thickness (residual thickness) of the portion of the lower metal sheet 10 where the main grooves 31 to 34 and the communication grooves 51 to 54 are formed is about 50 μm to 150 μm, concave deformation is suppressed. Therefore, it may be effective to arrange the first to fourth protrusions 41a to 44a in a staggered manner. Furthermore, even when oxygen-free copper is used as a material with good thermal conductivity, it may be difficult to suppress concave deformation due to the low mechanical strength of the material. Even when formed from oxygen-free copper, concave deformation can be effectively suppressed.

As described above, according to this embodiment, at the first intersection P1, the side wall 36 of the pair of side walls 35, 36 of the second mainstream groove 32 opposite to the side of the first communication groove 51 can be arranged, so that even if the lower metal sheet 10 and the upper metal sheet 20 are recessed inward along the first communication groove 51 due to the pressure of the outside air, the recess can be prevented from crossing the second mainstream groove 32. Similarly, at the second intersection P2, the side wall 35 of the pair of side walls 35, 36 of the second mainstream groove 32 opposite to the side of the second communication groove 52 can be arranged, so that even if the lower metal sheet 10 and the upper metal sheet 20 are recessed along the first communication groove 51 due to the pressure of the outside air, the recess can be prevented from crossing the second mainstream groove 32. Therefore, the flow path cross-sectional area of the second mainstream groove 32 can be secured, and the flow of the working fluid 2 can be prevented from being obstructed. As a result, the transport function of the liquid working fluid 2 can be improved, and the heat transport efficiency can be improved.

In addition, according to this embodiment, the second mainstream groove 32 of the liquid flow path section 30 includes a first intersection P1 where the first communication groove 51 faces the second convex portion 42a, and a second intersection P2 where the second communication groove 52 faces the first convex portion 41a. As a result, the side wall 36 of the pair of side walls 35, 36 of the second mainstream groove 32 opposite the side of the first communication groove 51 can be arranged at the first intersection P1, and the side wall 35 opposite the side of the second communication groove 52 can be arranged at the second intersection P2. Therefore, the working fluid 2 heading toward the evaporation section 11 can be continuously given a capillary action. In addition, since the capillary action can be given to the working fluid 2 in the second mainstream groove 32 by the side walls 35, 36 arranged on the opposite sides at the first intersection P1 and the second intersection P2, the capillary action given to the working fluid 2 in the second mainstream groove 32 can be equalized in the second direction Y. As a result, the driving force of the working fluid 2 toward the evaporation section 11 is prevented from decreasing at the intersections P1 and P2, improving the transport function of the liquid working fluid 2 and improving heat transport efficiency.

In addition, according to this embodiment, the first intersection P1 and the second intersection P2 of the second mainstream groove 32 are adjacent to each other. This allows the capillary action acting on the working fluid 2 in the second mainstream groove 32 to be equalized in the width direction.

Further, according to the present embodiment, the plurality of first intersections P1 and the plurality of second intersections P2 of the second mainstream groove 32 are arranged alternately. Thereby, the capillary action applied to the working fluid 2 in the second mainstream groove 32 can be made even more uniform.

In addition, according to this embodiment, the liquid flow path section 30 has a third mainstream groove 33, and the third mainstream groove 33 includes a first intersection P1 where the second communication groove 52 faces the third convex portion 43a, and a second intersection P2 where the third communication groove 53 faces the second convex portion 42a. As a result, in the same manner as the second mainstream groove 32 described above, even if the lower metal sheet 10 and the upper metal sheet 20 are recessed inward by the pressure of the outside air, the recess can be prevented from crossing the third mainstream groove 33. In addition, the capillary action imparted to the working fluid 2 in the third mainstream groove 33 can be made uniform. Therefore, the flow path cross-sectional area of the third mainstream groove 33 can be secured. In particular, in this embodiment, the first mainstream groove 31 and the fourth mainstream groove 34 also include the same first intersection P1 and second intersection P2, so that the capillary action imparted to the working fluid 2 throughout the entire liquid flow path section 30 can be equalized and the flow path cross-sectional area of each of the main mainstream grooves 31 to 34 can be secured, further improving the transport function of the working fluid 2.

Further, according to the present embodiment, since the first intersection P1 and the second intersection P2 of the third mainstream groove 33 are adjacent to each other, uneven application of capillary action can be further suppressed. . In particular, since the plurality of first intersections P1 and the plurality of second intersections P2 of the third mainstream groove 33 are arranged alternately, the capillary action imparted to the working fluid 2 in the third mainstream groove 33 is further enhanced. Further equalization can be achieved.

In addition, according to this embodiment, the lower surface 22a of the upper flow path wall portion 22 of the upper metal sheet 20, which abuts against the upper surface 13a of the lower flow path wall portion 13, is flat and covers the second mainstream groove 32. This allows two right-angled or acute-angled corners 37 (see FIG. 7) to be formed in the cross section of each of the mainstream grooves 31-34 and each of the connecting grooves 51-54, enhancing the capillary action acting on the working fluid 2 in each of the mainstream grooves 31-34 and each of the connecting grooves 51-54.

In addition, according to this embodiment, the width w1 of the first to fourth main grooves 31 to 34 is greater than the width w2 of the first to fourth convex portions 41a to 44a. This increases the proportion of the upper surface 13a of the lower flow passage wall portion 13 that is occupied by the first to fourth main grooves 31 to 34. This improves the transport function of the liquid working fluid 2.

Furthermore, according to this embodiment, the width w3 of the first to fourth communication grooves 51 to 54 is smaller than the width w1 of the first to fourth main grooves 31 to 34. As a result, while the liquid working fluid 2 is being transported toward the evaporation section 11 in each of the main grooves 31 to 34, the working fluid 2 can be prevented from flowing into the communication grooves 51 to 54, and the transport function of the working fluid 2 can be improved. On the other hand, if dryout occurs in any of the main grooves 31 to 34, the working fluid 2 can be moved from the adjacent main groove 31 to 34 through the corresponding communication groove 51 to 54, and the dryout can be quickly eliminated and the transport function of the working fluid 2 can be secured.

In the present embodiment described above, at the first intersection P1 of the second main flow groove 32, the entire first communication groove 51 faces the second convex portion 42a, and at the second intersection P2, , an example has been described in which the entire second communication groove 52 faces the first convex portion 41a. However, the invention is not limited to this, and at the first intersection P1, a part of the first communication groove 51 (a part of the area in the width direction (first direction X) of the first communication groove 51) is It is sufficient that it faces the second convex portion 42a. Further, at the second intersection P2, a portion of the second communication groove 52 only needs to face the first convex portion 41a. That is, when viewed in the second direction Y, if the first communication groove 51 and the second communication groove 52 do not entirely overlap (the first communication groove 51 and the second communication groove 52 are arranged in a straight line) (if not), they may partially overlap. Even in this case, the side wall 36 of the second mainstream groove 32 can be disposed in a part of the first intersection P1 in the first direction X, and a part of the second intersection P2 in the first direction The side wall 35 of the second main flow groove 32 can be arranged in the section. Therefore, it is possible to prevent the capillary action in the direction toward the evaporation section 11 from being lost at the first intersection P1. The same applies to the first intersection P1 and the second intersection P2 in each of the first main flow groove 31, the third main flow groove 33, and the fourth main flow groove 34.

In the above-described embodiment, an example has been described in which the first to fourth main grooves 31 to 34 each include a first intersection portion P1 and a second intersection portion P2. However, this is not limited to the above, and it is sufficient that at least one of the main grooves 31 to 34 in the liquid flow path section 30 includes the first intersection portion P1 and the second intersection portion P2.

For example, the liquid flow path section 30 may have a configuration as shown in FIG. 14. In the form shown in FIG. 14, the second main flow groove 32 and the fourth main flow groove 34 include a first intersection P1 and a second intersection P2, similar to the form shown in FIG. However, the first mainstream groove 31 and the third mainstream groove 33 do not include the first intersection P1 and the second intersection P2 as shown in FIG. 6 . That is, in the first mainstream groove 31, the fourth communication groove 54 and the first communication groove 51 extending in the second direction Y are arranged in a straight line, and the first main flow groove 31, the fourth communication groove 54, and the first communication groove 51 extend in the second direction Y. A third intersection P3 is formed where the communication grooves 51 intersect in a cross shape. Similarly, in the third main flow groove 33, the second communication groove 52 and the third communication groove 53 extending in the second direction Y are arranged in a straight line, and the third main flow groove 33, the second communication groove 52, and the third communication groove 53 extend in the second direction Y. A third intersection P3 is formed where the three communication grooves 53 intersect in a cross shape. Even in such a configuration, the second mainstream groove 32 and the fourth mainstream groove 34 include the first intersection P1 and the second intersection P2, so that the liquid working fluid in the liquid flow path section 30 is 2 transportation function can be improved.

Furthermore, in the present embodiment described above, an example has been described in which a plurality of first intersection portions P1 and second intersection portions P2 are provided in each of the main stream grooves 31 to 34 and arranged alternately. However, it is not limited to this. For example, if each of the main flow grooves 31 to 34 includes one first intersection P1 and one second intersection P2, the transport function of the hydraulic fluid 2 can be improved. Furthermore, although an example has been described in which the first intersection portion P1 and the second intersection portion P2 are adjacent to each other in each of the main flow grooves 31 to 34, the present invention is not limited to this. For example, in each of the main grooves 31 to 34, the communication grooves 51 to 54 on both sides are arranged in a straight line between the first intersection P1 and the second intersection P2, and the communication grooves 51 to 54 are arranged in a straight line between the first intersection P1 and the second intersection P2. An intersection (for example, P3 shown in FIG. 14) may be formed where 54 intersects in a cross shape. Even in this case, the first intersection P1 and the second intersection P2 can improve the transport function of the liquid hydraulic fluid 2 in the liquid flow path section 30.

Furthermore, in the present embodiment described above, an example has been described in which the first to fourth main grooves 31 to 34 and the first to fourth communication grooves 51 to 54 are perpendicular to each other. However, the present invention is not limited to this, and the first to fourth main grooves 31 to 34 and the first to fourth communication grooves 51 to 54 do not need to be perpendicular to each other as long as they can intersect with each other.

For example, as shown in FIG. 15, the direction in which the communication grooves 51-54 are aligned may be inclined with respect to the first direction X and the second direction Y. In this case, the inclination angle θ of the communication grooves 51-54 with respect to the first direction X is arbitrary. In the example shown in FIG. 15, the planar shape of each of the convex portions 41a-44a is a parallelogram. If such a shape is adopted for a rectangular vapor chamber 1, the four outer edges 1a, 1b (see FIG. 2) that form the out-of-plane contour of the vapor chamber 1 and the communication grooves 51-54 will no longer be perpendicular. In this case, it is possible to prevent deformation such as bending at the fold lines extending in the second direction Y, and it is possible to prevent the grooves 31-34, 51-54 of the liquid flow path portion 30 from being crushed.

The first to fourth main grooves 31 to 34 do not have to be formed in a straight line. For example, in FIG. 16, the main grooves 31 to 34 extend in a meandering manner rather than in a straight line, and generally extend in the first direction X. More specifically, a pair of side walls 35, 36 of the main groove 31 are formed such that curved concave portions and curved convex portions are alternately arranged and smoothly connected in a continuous manner. When the main grooves 31 to 34 are formed as shown in FIG. 16, the contact area between the working fluid 2 and the convex portions 41a to 44a increases, and the cooling efficiency of the working fluid 2 can be improved.

In the above-described embodiment, an example has been described in which the protrusions 41a to 44a are arranged in a staggered rectangular pattern throughout each liquid flow path section 30. However, this is not limited to the above, and at least some of the protrusions 41a to 44a may be arranged in a shape as shown in FIG. 15 or FIG. 16. Furthermore, the protrusions 41a to 44a may be arranged in a combination of at least two of the staggered pattern shown in FIG. 6, the arrangement in FIG. 15, and the arrangement in FIG. 16.

Furthermore, in the present embodiment described above, an example has been described in which the first convex portion 41a, the second convex portion 42a, the third convex portion 43a, and the fourth convex portion 44a have the same shape. However, the present invention is not limited to this, and the first to fourth convex portions 41a to 44a may have mutually different shapes.

For example, the lengths in the first direction X of the second convex portion 42a and the fourth convex portion 44a may be longer than those of the first convex portion 41a and the third convex portion 43a, as shown in FIG. In the form shown in FIG. 17, in the second mainstream groove 32 and the fourth mainstream groove 34, two first intersections P1 are interposed between two second intersections P2. That is, as shown in FIG. 6, the first intersections P1 and the second intersections P2 are not arranged alternately. Further, in the first mainstream groove 31 and the third mainstream groove 33, two second intersections P2 are interposed between the two first intersections P1, and the first intersection P1 and the second intersection P2 are interposed between the two first intersections P1. are not arranged alternately. Even in this case, the first intersection P1 and the second intersection P2 can improve the transport function of the liquid hydraulic fluid 2 in the liquid flow path section 30.

In the above-described embodiment, an example has been described in which the upper flow passage wall portion 22 of the upper metal sheet 20 extends in an elongated shape along the first direction X of the vapor chamber 1. However, this is not limited to this, and the shape of the upper flow passage wall portion 22 is arbitrary. For example, the upper flow passage wall portion 22 may be formed as a cylindrical boss. Even in this case, it is preferable to arrange the upper flow passage wall portion 22 so that it overlaps the lower flow passage wall portion 13 in a plan view, and to abut the lower surface 22a of the upper flow passage wall portion 22 against the upper surface 13a of the lower flow passage wall portion 13.

In addition, in the above-described embodiment, an example has been described in which the upper metal sheet 20 has the upper steam flow path recess 21, but this is not limited thereto, and the upper metal sheet 20 may be formed as a flat plate overall and may not have the upper steam flow path recess 21. In this case, the lower surface 20a of the upper metal sheet 20 abuts against the upper surface 13a of the lower flow path wall portion 13 as a second abutment surface, thereby improving the mechanical strength of the vapor chamber 1.

Furthermore, in the present embodiment described above, an example has been described in which the lower metal sheet 10 has the lower vapor channel recess 12 and the liquid channel section 30. However, the present invention is not limited to this, and if the upper metal sheet 20 has the upper steam flow path recess 21, the lower metal sheet 10 does not have the lower steam flow path recess 12, and the liquid flow The path portion 30 may be provided on the upper surface 10a of the lower metal sheet 10. In this case, as shown in FIG. 18, the region of the upper surface 10a where the liquid flow path portion 30 is formed is the region facing the upper steam flow path recess 21 in addition to the region facing the upper flow path wall portion 22. It may also be formed in a region other than the upper channel wall portion 22. In this case, the number of mainstream grooves 31 to 34 constituting the liquid flow path section 30 can be increased, and the transport function of the liquid working fluid 2 can be improved. However, the region forming the liquid flow path portion 30 is not limited to the form shown in FIG. 18, and may be any region as long as it can ensure the transport function of the liquid working fluid 2. Further, in the form shown in FIG. 18, the lower surface 22a (contact surface) of the upper flow path wall portion 22 of the upper metal sheet 20 is attached to one of the lower surfaces 20a of the upper metal sheet 20 in order to secure a steam flow path. The lower surface 22a of the upper flow path wall portion 22 comes into contact with a part of the region of the upper surface 10a of the lower metal sheet 10 where the liquid flow path portion 30 is formed.

In the above-described embodiment, an example has been described in which the first to fourth mainstream grooves 31 to 34 include the first intersection P1 and the second intersection P2. However, this is not limited to the above, and even if each mainstream groove 31 to 34 does not include the intersections P1 and P2, the proportion of the first to fourth mainstream grooves 31 to 34 on the upper surface 13a of the lower flow path wall 13 can be increased as long as the width w1 of the first to fourth mainstream grooves 31 to 34 is greater than the width w2 of the first to fourth convex portions 41a to 44a. Even in this case, the transport function of the working fluid 2 can be improved, and the heat transport efficiency can be improved.

(Second embodiment)
Next, a vapor chamber, an electronic device, a metal sheet for a vapor chamber, and a method for manufacturing a vapor chamber according to a second embodiment of the present invention will be described using FIGS. 19 to 23.

The second embodiment shown in Figures 19 to 23 differs mainly in that the widths of the first to fourth connecting grooves are greater than the widths of the first to fourth main grooves, and the rest of the configuration is substantially the same as the first embodiment shown in Figures 1 to 18. Note that in Figures 19 to 23, the same parts as those in the first embodiment shown in Figures 1 to 18 are given the same reference numerals and detailed descriptions are omitted.

As shown in FIG. 19, in this embodiment, the width w3' of the first to fourth communication grooves 51 to 54 is larger than the width w1 of the first to fourth mainstream grooves 31 to 34 (more specifically, the width of the first to fourth mainstream groove main bodies 31a to 34a described later). The width w3' of the communication grooves 51 to 54 may be, for example, 40 μm to 300 μm. In this embodiment, as shown in FIG. 20 and FIG. 21, an example will be described in which the cross-sectional shapes of the main mainstream grooves 31 to 34 and the cross-sectional shapes of the communication grooves 51 to 54 are curved. In this case, the widths of the grooves 31 to 34 and 51 to 54 are the widths of the grooves on the upper surface 13a of the lower flow path wall portion 13. Similarly, the widths of the convex portions 41a to 44a described later are the widths of the convex portions on the upper surface 13a.

Incidentally, even in this embodiment, the lower surface 22a of the upper flow path wall portion 22 of the upper metal sheet 20 is formed flat. As a result, the first to fourth mainstream grooves 31 to 34 of the liquid flow path portion 30 are covered with the flat lower surface 22a. In this case, as shown in FIG. 20, a pair of side walls 35, 36 extending in the first direction X of the first to fourth mainstream grooves 31 to 34 and the lower surface 22a of the upper flow path wall portion 22 can form two right-angled or acute-angled corners 37, and the capillary action at these two corners 37 can be enhanced. In other words, even if the cross sections of the first to fourth mainstream grooves 31 to 34 are formed curved, the capillary action at the corners 37 can be enhanced.

Similarly, the first to fourth communication grooves 51 to 54 of the liquid flow path section 30 are covered with a flat lower surface 22a. In this case, as shown in FIG. 21, a pair of side walls 55, 56 extending in the second direction Y of the first to fourth communication grooves 51 to 54 and the lower surface 22a of the upper flow path wall section 22 can form two right-angled or acute-angled corners 57, and the capillary action at these two corners 57 can be enhanced. In other words, even if the cross sections of the first to fourth communication grooves 51 to 54 are formed in a curved shape, the capillary action at the corners 57 can be enhanced.

Here, the liquid working fluid 2 condensed from steam enters the first to fourth main flow grooves 31 to 34 through the first to fourth communication grooves 51 to 54, as described later. Therefore, by increasing the capillary action of the first to fourth communication grooves 51 to 54, the condensed liquid working fluid 2 can smoothly enter the first to fourth mainstream grooves 31 to 34. Due to the capillary action of the first to fourth communication grooves 51 to 54, the condensed liquid working fluid 2 flows not only from the main stream groove 31 on the side closer to the steam flow path recesses 12 and 21 but also from the steam flow path recesses 12 and 21. It can smoothly enter the first to fourth mainstream grooves 31 to 34 on the far side, and the transport function of the condensed liquid working fluid 2 can be improved. Furthermore, by making the width w3' of the first to fourth communication grooves 51 larger than the width w1 of the first to fourth main flow grooves 31 to 34, the operation within the first to fourth communication grooves 51 to 54 is The flow path resistance of the liquid 2 can be reduced, and in this respect as well, the condensed liquid working liquid 2 can smoothly enter the first to fourth main flow grooves 31 to 34. The working fluid 2 that has entered the first to fourth mainstream grooves 31 to 34 can be smoothly transported toward the evaporation section 11 by the capillary action of the first to fourth mainstream grooves 31 to 34. Therefore, the transport function of the liquid working fluid 2 can be improved as a whole of the liquid flow path section 30.

In addition, both ends of the first to fourth convex portions 41a to 44a in the first direction X are rounded in plan view. That is, each of the convex portions 41a to 44a is formed in a rectangular shape when viewed from a broad perspective, but the corners are provided with rounded curved portions 45. As a result, the corners of each of the convex portions 41a to 44a are smoothly curved, reducing the flow resistance of the liquid working fluid 2. In addition, an example is shown in which two curved portions 45 are provided at the right end and the left end of the convex portions 41a to 44a in FIG. 19, and a straight portion 46 is provided between these two curved portions 45. For this reason, the width w3' of the first to fourth communication grooves 51 to 54 is the distance between the straight portions 46 of the convex portions 41a to 44a adjacent to each other in the first direction X. As shown in FIG. 6, the same applies when the curved portions 45 are not formed in each of the convex portions 41a to 44a. However, the shape of the ends of the convex portions 41a to 44a is not limited to this. For example, the right end and the left end may be formed so that the entire end is curved (e.g., semicircular) without the straight portion 46. In this case, the width w3' of each communication groove 51 to 54 is the minimum distance between adjacent convex portions 41a to 44a in the first direction X. Note that, for clarity of illustration, in FIG. 19, the curved portion 45 and the straight portion 46 are representatively shown in the fourth convex portion 44a shown at the bottom.

As shown in FIGS. 20 and 21, in the present embodiment, the depth h3' of the first to fourth communication grooves 51 to 54 is greater than the depth h1 of the first to fourth main flow grooves 31 to 34. Specifically, the depth is larger than the depths of first to fourth main groove main body portions 31a to 34a, which will be described later. Here, as described above, when the cross-sectional shape of each main flow groove 31-34 and the cross-sectional shape of each communication groove 51-54 are formed in a curved shape, the depth of the grooves 31-34, 51-54 is the depth at the deepest position in the groove. The depth h3' of the first to fourth communication grooves 51 to 54 may be, for example, 10 μm to 250 μm.

In this embodiment, as shown in FIG. 22, the depth h1' of the first intersection P1 and the second intersection P2 of the first to fourth mainstream grooves 31 to 34 is deeper than the depth h1 of the portions of the mainstream grooves 31 to 34 other than the first intersection P1 and the second intersection P2. That is, the first to fourth mainstream grooves 31 to 34 further include the first to fourth mainstream groove main bodies 31a to 34a provided between the first intersection P1 and the second intersection P2. The first to fourth mainstream groove main bodies 31a to 34a are portions located between the adjacent convex portions 41a to 44a, and are portions located between the adjacent first intersection P1 and the second intersection P2. The depth h1' of the first intersection P1 and the second intersection P2 is deeper than the depth h1 of the first to fourth mainstream groove main bodies 31a to 34a. The depth h1' of the first intersection P1 is the depth at the deepest position of the first intersection P1, and the depth h1' of the second intersection P2 is the depth at the deepest position of the second intersection P2.

19 and 22, the depth h1' of the first intersection P1 and the second intersection P2 of the first mainstream groove 31 is deeper than the depth h1 of the portion (first mainstream groove main body 31a) between the fourth convex portion 44a and the first convex portion 41a of the first mainstream groove 31. Similarly, the depth h1' of the first intersection P1 and the second intersection P2 of the second mainstream groove 32 is deeper than the depth h1 of the portion (second mainstream groove main body 32a) between the first convex portion 41a and the second convex portion 42a of the second mainstream groove 32. The depth h1' of the first intersection P1 and the second intersection P2 of the third mainstream groove 33 is deeper than the depth h1 of the portion (third mainstream groove main body 33a) between the second convex portion 42a and the third convex portion 43a of the third mainstream groove 33. The depth h1' of the first intersection P1 and the second intersection P2 of the fourth mainstream groove 34 is deeper than the depth h1 of the portion of the fourth mainstream groove 34 between the third convex portion 43a and the fourth convex portion 44a (the fourth mainstream groove main body portion 34a).

Further, the depth h1' of the first intersection P1 and the second intersection P2 of the first to fourth main flow grooves 31 to 34 is deeper than the depth h3' of the first to fourth communication grooves 51 to 54. You can leave it there. The depth h1' of the first intersection P1 and the second intersection P2 may be, for example, 20 μm to 300 μm.

As shown in FIG. 19, the first to fourth convex portions 41a to 44a are generally rectangular as described above, but are different from the planar shapes of the first to fourth convex portions 41a to 44a shown in FIG. 6. That is, the first to fourth convex portions 41a to 44a include a pair of first to fourth convex portion ends 41b to 44b provided on both sides in the first direction X, and a pair of first to fourth convex portion intermediate portions 41c to 44c provided between the pair of first to fourth convex portion ends 41b to 44b. Of these, the width w4 of the first to fourth convex portion intermediate portions 41c to 44c is smaller than the width w2 of the first to fourth convex portion ends 41b to 44b (corresponding to the width w2 of the first to fourth convex portions 41a to 44a described above).

More specifically, the width w4 of the first convex intermediate portion 41c is smaller than the width w2 of the first convex end portion 41b, and the walls of the first convex portion 41a (i.e., the side wall 36 of the first main groove 31 and the side wall 35 of the second main groove 32) are smoothly curved so as to be concave toward the inside of the first convex portion 41a. For this reason, the width w4 of the first convex intermediate portion 41c is the minimum distance between the two walls. Similarly, the width w4 of the second convex intermediate portion 42c is smaller than the width w2 of the second convex end portion 42b, and the walls of the second convex portion 42a (i.e., the side wall 36 of the second main groove 32 and the side wall 35 of the third main groove 33) are smoothly curved so as to be concave toward the inside of the second convex portion 42a. The width w4 of the third convex intermediate portion 43c is smaller than the width w2 of the third convex end portion 43b, and the walls of the third convex portion 43a (i.e., the sidewall 36 of the third main groove 33 and the sidewall 35 of the fourth main groove 34) are smoothly curved so as to be recessed toward the inside of the third convex portion 43a. The width w4 of the fourth convex intermediate portion 44c is smaller than the width w2 of the fourth convex end portion 44b, and the walls of the fourth convex portion 44a (i.e., the sidewall 36 of the fourth main groove 34 and the sidewall 35 of the first main groove 31) are smoothly curved so as to be recessed toward the inside of the fourth convex portion 44a. The width w4 of the first to fourth convex intermediate portions 41c to 44c may be, for example, 15 μm to 175 μm.

As described above, the depth h3' of the first to fourth communication grooves 51 to 54 is deeper than the depth h1 of the first to fourth main groove body portions 31a to 34a of the first to fourth main grooves 31 to 34, and the depth h1' of the first intersection portion P1 and the second intersection portion P2 of the first to fourth main grooves 31 to 34 is deeper than the depth h1 of the first to fourth main groove body portions 31a to 34a. As a result, a buffer region Q deeper than the depth h1 of the first to fourth main groove body portions 31a to 34a is formed in the region from the second intersection portion P2 to the first intersection portion P1 via the first to fourth communication grooves 51 to 54. This buffer region Q is capable of storing the liquid working fluid 2.

More specifically, for example, a buffer region Q deeper than the depth h1 of the first mainstream groove body portion 31a and the second mainstream groove body portion 32a is formed in the region extending from the second intersection portion P2 of the first mainstream groove 31 to the first intersection portion P1 of the second mainstream groove 32 via the first connecting groove 51. Normally, each of the mainstream grooves 31-34 and each of the connecting grooves 51-54 of the liquid flow path portion 30 is filled with liquid working fluid 2. Therefore, since the depth (h1' and h3') of the buffer region Q is deeper than the depth h1 of the first to fourth mainstream groove body portions 31a-34a, it is possible to store a large amount of working fluid 2 in the buffer region Q. As described above, each of the mainstream grooves 31-34 and each of the connecting grooves 51-54 are filled with the working fluid 2, so that the working fluid 2 can be stored in the buffer region Q regardless of the attitude of the vapor chamber 1.

Similarly, the second mainstream groove body 32a and the third mainstream A buffer region Q is formed which is deeper than the depth h1 of the groove main body portion 33a. A third mainstream groove body 33a and a fourth mainstream groove body 34a are provided in a region extending from the second intersection P2 of the third mainstream groove 33 to the first intersection P1 of the fourth mainstream groove 34 via the third communication groove 53. A buffer region Q deeper than the depth h1 is formed. In a region extending from the second intersection P2 of the fourth mainstream groove 34 to the first intersection P1 of the first mainstream groove 31 via the fourth communication groove 54, the fourth main groove body 34a and the first mainstream groove body 31a are A buffer region Q deeper than the depth h1 is formed.

In addition, a large number of first intersections P1 and second intersections P2 are formed in each liquid flow path section 30 of the vapor chamber 1, and if the depth h1' of at least one of the intersections P1, P2 is deeper than the depth h1 of the main groove body parts 31a to 34a (or the depth h3' of the communication grooves 51 to 54), the storage performance of the working fluid 2 at the intersections P1, P2 can be improved. This storage performance improves as the number of intersections P1, P2 having a depth h1' deeper than the depth h1 of the main groove body parts 31a to 34a increases, so it is preferable that the depth h1' of all intersections P1, P2 have the same depth. However, it is clear that the storage performance of the working fluid 2 can be improved even if the depth h1' of some intersections P1, P2 is not deeper than the depth h1 of the main groove body parts 31a to 34a due to manufacturing errors, etc. The same applies to the depth h3' of the communication grooves 51 to 54.

Here, a method for checking the widths and depths of the main stream grooves 31 to 34 and the widths and depths of the communication grooves 51 to 54 from the completed vapor chamber 1 will be explained. Generally, the main stream grooves 31 to 34 and the communication grooves 51 to 54 are not visible from the outside of the vapor chamber 1. For this reason, there is a method of checking the width and depth of the main stream grooves 31 to 34 and the communication grooves 51 to 54 from the cross-sectional shape obtained by cutting the completed vapor chamber 1 at a desired position.

Specifically, first, the vapor chamber 1 was cut into a 10 mm square piece using a wire saw to prepare a sample. Subsequently, the sample is embedded in a resin while degassing under vacuum so that the resin enters the vapor flow path recesses 12 and 21 and the liquid flow path portion 30 (mainstream grooves 31 to 34 and communication grooves 51 to 54). Next, trimming is performed using a diamond knife to obtain the desired cross section. At this time , a diamond knife of a microtome (Ultra Microtome manufactured by Leica Microsystems) is used to perform trimming to a portion 40 μm away from the measurement target position. For example, if the pitch of the communication grooves 51 to 54 is 200 μm, by cutting 160 μm from the communication groove 51 to 54 next to the communication groove 51 to 54 that is the purpose of measurement, it is possible to cut 40 μm from the communication groove 51 to 54 that is the purpose of measurement. Distant parts can be identified. Next, a cut surface for observation is prepared by cutting the trimmed cut surface. At this time, using a cross-sectional sample preparation device (cross-section polisher manufactured by J OEL), the cut surface is polished by ion beam processing with the protrusion width set to 40 μm, the voltage to 5 kV, and the time to 6 hours. Thereafter, the cut surface of the obtained sample is observed. At this time, the cut surface is observed using a scanning electron microscope (scanning electron microscope manufactured by Carl Zeiss) with the voltage set to 5 kV, the working distance set to 3 mm, and the observation magnification set to 500 times. In this way, the width and depth of the main grooves 31 to 34 and the communication grooves 51 to 54 can be measured. Note that the observation magnification standard during photographing is Polaroid 545 .

By the way, as described above, the width w3' of the first to fourth communication grooves 51 to 54 is larger than the width w1 of the first to fourth main flow grooves 31 to 34. As a result, the buffer region Q has a larger opening than the first to fourth main groove main body portions 31a to 34a. Therefore, in the second half-etching step shown in FIG. 10, more of the etching solution enters the buffer region Q than the first to fourth main groove main portions 31a to 34a. As a result, the buffer region Q is eroded by the etching solution, and the depth of the buffer region Q becomes deeper. The portions of the buffer region Q corresponding to the first intersection P1 and the second intersection P2 communicate with the first to fourth main groove main body parts 31a to 34a, so that the first to fourth communication grooves Etching solution can penetrate more easily than in Nos. 51 to 54. As a result, the depth h1' of the first intersection P1 and the second intersection P2 can be deeper than the depth h3' of the first to fourth communication grooves 51 to 54. In this way, a buffer region Q as shown in FIG. 22 is formed.

In addition, as a large amount of etching solution enters the buffer region Q, the walls of the first to fourth convex portions 41a to 44a (side walls 35, 36 of the first to fourth main grooves 31 to 34) that face the first intersection P1 and the second intersection P2 are eroded by the etching solution. As a result, the walls of each convex portion 41a to 44a are eroded by the etching solution, forming a smoothly curved shape that is recessed toward the inside of each convex portion 41a to 44a.

In the second half-etching step shown in FIG. 10, as described above, a second resist film is formed in a pattern on the upper surface 13a of the lower flow path wall portion 13, and the etching liquid enters the resist openings of the second resist film to form the first to fourth main grooves 31 to 34 and the first to fourth connecting grooves 51 to 54. Even if the resist openings are formed parallel to the first direction X and the second direction Y, the width w3' of the first to fourth connecting grooves 51 to 54 is larger than the width w1 of the first to fourth main grooves 31 to 34, so that the etching liquid easily enters the buffer region Q. Therefore, the buffer region Q as described above can be formed.

In the vapor chamber 1 according to this embodiment, the vapor of the working fluid 2 diffused to the periphery of the vapor chamber 1 is cooled and condensed. The condensed working fluid 2 passes through the first to fourth connecting grooves 51 to 54 and enters the main groove 31. As described above, the width w3' of the first to fourth connecting grooves 51 to 54 is larger than the width w1 of the first to fourth main grooves 31 to 34, so the flow resistance of the working fluid 2 in each connecting groove 51 to 54 is small. Therefore, the liquid working fluid 2 adhering to the wall surface of each vapor flow recess 12, 21 passes through each connecting groove 51 to 54 and smoothly enters each main groove 31 to 34. Then, each main groove 31 to 34 and each connecting groove 51 to 54 are filled with the liquid working fluid 2.

When the working fluid 2 filled in each of the main grooves 31-34 is transported toward the evaporation section 11, a portion of the working fluid 2 passes through the first intersection P1 and the second intersection P2 toward the evaporation section 11. At the first intersection P1 and the second intersection P2, the working fluid 2 obtains a driving force toward the evaporation section 11 mainly due to the capillary action of the corners 37 formed by the side walls 35, 36 of the first to fourth main grooves 31-34 and the lower surface 22a of the upper flow channel wall 22.

On the other hand, a part of the working fluid 2 heading toward the evaporator 11 is drawn into and stored in the buffer region Q formed by the first intersection P1 or the second intersection P2.

Here, when dryout occurs in the first to fourth mainstream groove body parts 31a to 34a, the working fluid 2 stored in the buffer region Q moves toward the area where the dryout occurred. More specifically, for example, when dryout occurs in the first mainstream groove body part 31a, the working fluid 2 moves from the buffer region Q closest to the area where the dryout occurred to the area where the dryout occurred due to the capillary action of the first mainstream groove body part 31a. As a result, the area where the dryout occurred is filled with the working fluid 2, and the dryout is resolved.

In addition, in the first to fourth mainstream groove body portions 31a to 34a, when bubbles are generated in the liquid working fluid 2 due to its vapor, the bubbles are drawn into and held in the buffer region Q on the downstream side (the side of the evaporation section 11). Because the depth of the buffer region Q is deeper than the depth h1 of the first to fourth mainstream groove body portions 31a to 34a, the bubbles drawn into the buffer region Q are prevented from moving from the buffer region Q to the mainstream groove body portions 31a to 34a. Therefore, the buffer region Q can capture the bubbles generated in the mainstream groove body portions 31a to 34a, and can prevent the flow of the working fluid 2 to the evaporation section 11 from being obstructed by the bubbles.

As described above, according to the present embodiment, the width w3' of the first to fourth communication grooves 51 to 54 is larger than the width w1 of the first to fourth main flow grooves 31 to 34. This makes it possible to reduce the flow path resistance of the hydraulic fluid 2 in each of the communication grooves 51 to 54. Therefore, the liquid working fluid 2 condensed from steam can smoothly enter each of the main stream grooves 31 to 34. That is, it is possible to smoothly enter not only the mainstream grooves 31 to 34 on the side closer to the steam flow path recesses 12 and 21 but also the mainstream grooves 31 to 34 on the side farther from the steam flow path recesses 12 and 21, and the condensed The transport function of the liquid hydraulic fluid 2 can be improved. As a result, the transport function of the liquid working fluid 2 can be improved, and the heat transport efficiency can be improved.

In addition, according to this embodiment, the depth h3' of the first to fourth communication grooves 51 to 54 is deeper than the depth h1 of the first to fourth main grooves 31 to 34. This allows a buffer region Q for storing the working fluid 2 to be formed in each communication groove 51 to 54. Therefore, when dryout occurs in the main grooves 31 to 34, the working fluid 2 stored in the buffer region Q can be moved to the area where the dryout occurs. This makes it possible to eliminate the dryout and restore the transport function of the working fluid 2 in each main groove 31 to 34. In addition, when air bubbles are generated in the main grooves 31 to 34, the air bubbles can be drawn into the buffer region Q and captured. In this respect, too, the transport function of the working fluid 2 in each main groove 31 to 34 can be restored.

In addition, according to this embodiment, the depth h1' of the first intersection P1 and the second intersection P2 of the first to fourth mainstream grooves 31 to 34 is deeper than the depth h1 of the first to fourth mainstream groove body portions 31a to 34a. This allows the buffer region Q to extend to the first intersection P1 and the second intersection P2. This increases the amount of hydraulic fluid 2 stored in the buffer region Q, making it easier to eliminate dryout.

In addition, according to this embodiment, the depth h1' of the first intersection P1 and the second intersection P2 of the first to fourth main grooves 31 to 34 is deeper than the depth h3' of the first to fourth communication grooves 51 to 54. This allows the depth of the buffer region Q to be deeper on the side closer to the area where dryout occurs. This allows the stored working fluid 2 to be smoothly moved to the area where dryout occurs, making it even easier to eliminate dryout.

Further, according to the present embodiment, the width w4 of the first to fourth convex intermediate portions 41c to 44c of the first to fourth convex portions 41a to 44a is the same as the width w4 of the first to fourth convex portion ends 41b to 44b. The width w2 is smaller than the width w2. Thereby, the planar area of the first intersection P1 and the second intersection P2 can be increased. Therefore, the amount of hydraulic fluid 2 stored in the buffer region Q can be increased, making it easier to eliminate dryout.

Further, according to the present embodiment, rounded curved portions 45 are provided at the corners of each of the convex portions 41a to 44a. As a result, the corners of each of the convex portions 41a to 44a can be formed into a smoothly curved shape, and the flow path resistance of the liquid working fluid 2 can be reduced.

Third Embodiment
Next, a vapor chamber, a metal sheet for a vapor chamber, and a method for manufacturing a vapor chamber according to a third embodiment of the present invention will be described with reference to FIGS.

In the third embodiment shown in FIGS. 23 to 25, the main flow groove protrusions protrude within the first to fourth main flow grooves, and the communication groove protrusions protrude within the first to fourth communication grooves. The main difference is that the second embodiment is protruded, and the other configurations are substantially the same as the second embodiment shown in FIGS. 19 to 22. Note that in FIGS. 23 to 25, the same parts as those in the second embodiment shown in FIGS. 19 to 22 are denoted by the same reference numerals, and detailed description thereof will be omitted.

As shown in FIG. 23, in this embodiment, the upper metal sheet 20 has multiple main groove convex portions 27 provided on the lower surface 20a. Each main groove convex portion 27 protrudes from the lower surface 20a into a corresponding one of the first to fourth main grooves 31 to 34 of the lower metal sheet 10. The lower end of the main groove convex portion 27 is spaced apart from the bottom of the main grooves 31 to 34, ensuring a flow path for the working fluid 2. In addition, each main groove convex portion 27 is formed to extend in the first direction X along the corresponding main groove 31 to 34.

The cross section of the main stream groove convex portion 27 is formed in a curved shape. Further, the side edges of the main stream groove convex portion 27 are in contact with or close to the side walls 35 and 36 of the first to fourth main stream grooves 31 to 34. As a result, the corner portion 37 formed by the side walls 35, 36 of the first to fourth mainstream grooves 31 to 34 and the lower surface 22a of the upper channel wall portion 22 is formed into a wedge shape (or an acute angle shape). In this way, the flow path cross section (flow path cross section in the second direction Y) defined by the main flow grooves 31 to 34 and the main flow groove convex portion 27 is formed in a crescent shape as shown in FIG. 23.

As shown in Figs. 24 and 25, in this embodiment, the upper metal sheet 20 has a plurality of communication groove protrusions 28 provided on the lower surface 20a. Each communication groove protrusion 28 protrudes from the lower surface 20a into a corresponding one of the first to fourth communication grooves 51 to 54 of the lower metal sheet 10. The lower end of the communication groove protrusion 28 is spaced from the bottom of the communication groove 51 to 54, ensuring a flow path for the working fluid 2. Each communication groove protrusion 28 is formed to extend in the second direction Y along the corresponding communication groove 51 to 54. At the first intersection P1 and the second intersection P2 of the first to fourth mainstream grooves 31 to 34, the above-mentioned mainstream groove protrusion 27 and the communication groove protrusion 28 intersect in a T-shape.

The cross section of the communicating groove convex portion 28 is formed in a curved shape similarly to the main stream groove convex portion 27 . Further, the side edges of the communication groove convex portion 28 are in contact with a pair of side walls 55 and 56 (see FIG. 19) extending in the second direction Y of the first to fourth communication grooves 51 to 54, or are in contact with the side walls 55 and 56. Close to each other. As a result, the corner portion 57 formed by the side walls 55, 56 of the first to fourth communication grooves 51 to 54 and the lower surface 22a of the upper channel wall portion 22 is formed into a wedge shape (or an acute angle shape). In this way, the flow path cross section (flow path cross section in the first direction X) defined by the communication grooves 51 to 54 and the communication groove convex portion 28 is formed in a crescent shape as shown in FIG. 24. In addition, the flow path cross section in the second direction Y is such that the flow path cross section in the second direction Y of the first to fourth communication grooves 51 to 54 is interposed between the flow path cross sections of the main flow grooves 31 to 34 shown in FIG. As shown in FIG. 25, it is formed in an elongated crescent shape. In addition, in FIG. 19, in order to make the drawing clear, only the side walls of the third communication groove 53 are labeled with numerals 55 and 56. The side walls 55, 56 correspond to the above-mentioned linear portions 46 of the convex portions 41a to 44a.

The main groove convex portion 27 and the connecting groove convex portion 28 can be formed, for example, by half-etching the upper metal sheet 20 to form the upper flow passage wall portion 22 and the like, and then pressing the upper metal sheet 20 alone. Alternatively, the main groove convex portion 27 and the connecting groove convex portion 28 can be formed by increasing the pressure applied to the lower metal sheet 10 and the upper metal sheet 20 in the permanent joining process shown in FIG. 12. That is, by increasing the pressure, a part of the upper flow passage wall portion 22 of the upper metal sheet 20 can be inserted into the first to fourth main grooves 31 to 34 and the first to fourth connecting grooves 51 to 54, thereby forming the main groove convex portion 27 and the connecting groove convex portion 28 having a curved cross section.

Thus, according to this embodiment, the main groove convex portion 27 protrudes from the lower surface 20a of the upper metal sheet 20 to the corresponding main groove 31-34 of the first to fourth main grooves 31-34 of the lower metal sheet 10. As a result, the corner portion 37 formed by the side walls 35, 36 of the first to fourth main grooves 31-34 and the lower surface 22a of the upper flow passage wall portion 22 can be made into a minute space defined by the side walls 35, 36 of the first to fourth main grooves 31-34 and the main groove convex portion 27. Therefore, the capillary action at the corner portion 37 can be enhanced. As a result, the transport function of the liquid working fluid 2 in each of the main grooves 31-34 can be improved, and the heat transport efficiency can be improved. In particular, even if the first intersection P1 and second intersection P2 of each of the main grooves 31-34 are configured as a buffer region Q as shown in FIG. 19, the working fluid 2 at the first intersection P1 and second intersection P2 can be given a high driving force toward the evaporation section 11 due to the capillary action of the main groove convex portion 27, and the transport function of the working fluid 2 can be effectively improved.

In addition, according to this embodiment, the cross section of the main groove convex portion 27 is formed in a curved shape. This allows the corner portion 37 to be shaped like a crescent-shaped end. This further enhances the capillary action at the corner portion 37.

In addition, according to this embodiment, the communication groove protrusions 28 protrude from the lower surface 20a of the upper metal sheet 20 into the corresponding communication grooves 51-54 of the first to fourth communication grooves 51-54 of the lower metal sheet 10. This makes it possible to make the corners 57 formed by the side walls 55, 56 of the first to fourth communication grooves 51-54 and the lower surface 22a of the upper flow path wall 22 into minute spaces defined by the side walls 55, 56 of the first to fourth communication grooves 51-54 and the communication groove protrusions 28. This makes it possible to enhance the capillary action at the corners 57.

Here, as described above, the liquid working fluid 2 condensed from the vapor passes through the first to fourth communication grooves 51 to 54 and enters the first to fourth mainstream grooves 31 to 34. Therefore, by enhancing the capillary action of the first to fourth communication grooves 51 to 54, the condensed liquid working fluid 2 can smoothly enter the first to fourth mainstream grooves 31 to 34. The capillary action of the first to fourth communication grooves 51 to 54 allows the condensed liquid working fluid 2 to smoothly enter not only the mainstream grooves 31 to 34 closer to the steam flow path recesses 12, 21, but also the mainstream grooves 31 to 34 farther from the steam flow path recesses 12, 21, improving the transport function of the condensed liquid working fluid 2. In addition, by making the width w3' of the first to fourth communication grooves 51 to 54 larger than the width w1 of the first to fourth main grooves 31 to 34, the flow resistance of the working fluid 2 in the first to fourth communication grooves 51 to 54 can be reduced, and in this respect, the condensed liquid working fluid 2 can be smoothly introduced into the first to fourth main grooves 31 to 34. The working fluid 2 that has entered the first to fourth main grooves 31 to 34 can be smoothly transported toward the evaporation section 11 by the capillary action of the first to fourth main grooves 31 to 34. Therefore, the liquid flow path section 30 as a whole can improve the transport function of the liquid working fluid 2. In addition, as described above, by increasing the capillary action of the first to fourth communication grooves 51 to 54, when dryout occurs, the working fluid 2 can be moved between the first to fourth main grooves 31 to 34 by the capillary action of the first to fourth communication grooves 51 to 54, and dryout can be eliminated.

Further, according to this embodiment, the cross section of the communicating groove convex portion 28 is formed in a curved shape. This allows the corner 57 to be shaped like a crescent-shaped end. Therefore, the capillary action at the corner 57 can be further enhanced.

In the above embodiment, the cross sections of the first to fourth main grooves 31 to 34 and the first to fourth connecting grooves 51 to 54 are curved. However, this is not limited to the above, and the cross sections of the first to fourth main grooves 31 to 34 and the first to fourth connecting grooves 51 to 54 may be rectangular, as shown in FIG. 7. Even in this case, the capillary action at the corners 37, 57 can be enhanced, and the transport function of the liquid working fluid 2 in the first to fourth main grooves 31 to 34 and the first to fourth connecting grooves 51 to 54 can be improved. In order to make the cross sections rectangular, it is preferable to form the main grooves 31 to 34 and the connecting grooves 51 to 54 by pressing or cutting.

Further, in the present embodiment described above, an example was described in which the width w3' of the first to fourth communication grooves 51 to 54 is larger than the width w1 of the first to fourth main flow grooves 31 to 34. . However, the present invention is not limited to this, and the width w3' of each of the communication grooves 51 to 54 does not have to be larger than the width w1 of each of the main flow grooves 31 to 34, as shown in FIG. That is, the effect of increasing the capillary action of the first to fourth mainstream grooves 31 to 34 by the main stream groove convex portion 27 and enhancing the transport function of the liquid working fluid 2 in the main stream grooves 31 to 34 is due to the effect of the communication grooves 51 to 54. This effect can be achieved regardless of the magnitude relationship between the width w3' and the width w1 of the main grooves 31 to 34. Similarly, the effect of increasing the capillary action of the first to fourth communication grooves 51 to 54 by the communication groove convex portion 28 and enhancing the transport function of the condensed liquid working fluid 2 is also due to the width w3 of the communication grooves 51 to 54. This can be achieved regardless of the magnitude relationship between ' and the width w1 of the main grooves 31 to 34.

The present invention is not limited to the above-described embodiments and modifications as they are, but can be implemented by modifying the constituent elements within the scope of the invention at the implementation stage. Moreover, various inventions can be formed by appropriately combining the plurality of components disclosed in the above embodiments and modified examples. Some components may be deleted from all the components shown in the embodiments and modifications. Furthermore, in each of the embodiments and modifications described above, the configuration of the lower metal sheet 10 and the configuration of the upper metal sheet 20 may be replaced.

Claims (5)

A vapor chamber containing a hydraulic fluid,
A first metal sheet;
a second metal sheet provided on the first metal sheet;
A vapor flow path portion through which the vapor of the working fluid passes;
a liquid flow path portion through which the liquid working fluid passes,
The liquid flow path portion is provided on a surface of the first metal sheet on the side of the second metal sheet,
the liquid flow path portion includes a first main groove extending in a first direction and through which the liquid working fluid passes, and a first convex portion row provided adjacent to the first main groove and including a plurality of first convex portions arranged in the first direction via a first communication groove,
Both ends of at least one of the first protrusions in the first direction are rounded in a plan view,
A vapor chamber , wherein the depth of the first communication groove is greater than the depth of the first main groove . A vapor chamber filled with hydraulic fluid,
a first metal sheet;
a second metal sheet provided on the first metal sheet;
a steam flow path portion through which the vapor of the working fluid passes;
a liquid flow path portion through which the liquid working fluid passes, the liquid flow path portion being disposed at a position different from the vapor flow path portion in plan view ;
The liquid flow path portion is provided on a surface of the first metal sheet on the second metal sheet side,
The liquid flow path portion includes a first convex row including a plurality of first convex portions arranged in a first direction via a first communication groove, and a first convex row extending in the first direction and through which the liquid hydraulic fluid passes. a first main stream groove; a second convex row including a plurality of second convexes arranged in the first direction via a second communication groove; and a second convex row extending in the first direction and through which the liquid hydraulic fluid passes. a second main stream groove, and a third convex row including a plurality of third convex portions arranged in the first direction via a third communication groove;
The first convex row, the first mainstream groove, the second convex row, the second mainstream groove, and the third convex row are arranged in this order in a second direction perpendicular to the first direction,
The length of at least one of the first convex portions in the first direction and the length of at least one of the third convex portions in the first direction are longer than the length of at least one of the second convex portions in the first direction. Also long, vapor chamber. housing and
a device contained within the housing;
An electronic device comprising: the vapor chamber according to claim 1 or 2 , in thermal contact with the device. A vapor chamber metal sheet for a vapor chamber having a vapor flow path portion in which a working fluid is sealed and through which the vapor of the working fluid passes, and a liquid flow path portion through which the liquid working fluid passes,
The first page and
a second surface provided on the opposite side to the first surface,
The liquid flow path section is provided on the first surface,
The liquid flow path section is provided next to a first mainstream groove that extends in a first direction and through which the liquid working fluid passes, and is arranged next to the first mainstream groove, and is arranged in the first direction via a first communication groove. a first convex row including a plurality of first convex portions,
Both ends of the at least one first convex portion in the first direction have a rounded shape in plan view,
A metal sheet for a vapor chamber, wherein the depth of the first communication groove is deeper than the depth of the first mainstream groove . A steam flow path portion in which a working fluid is sealed and through which the vapor of the working fluid passes, and a liquid flow path portion through which the liquid working fluid passes, which are arranged at a different position from the steam flow path portion in a plan view. A vapor chamber metal sheet for a vapor chamber having a liquid flow path section ,
The first page and
a second surface provided on the opposite side to the first surface,
The liquid flow path section is provided on the first surface,
The liquid flow path portion includes a first convex row including a plurality of first convex portions arranged in a first direction via a first communication groove, and a first convex row extending in the first direction and through which the liquid hydraulic fluid passes. a first main stream groove; a second convex row including a plurality of second convexes arranged in the first direction via a second communication groove; and a second convex row extending in the first direction and through which the liquid hydraulic fluid passes. a second main stream groove, and a third convex row including a plurality of third convex portions arranged in the first direction via a third communication groove;
The first convex row, the first mainstream groove, the second convex row, the second mainstream groove, and the third convex row are arranged in this order in a second direction perpendicular to the first direction,
The length of at least one of the first convex portions in the first direction and the length of at least one of the third convex portions in the first direction are longer than the length of at least one of the second convex portions in the first direction. Also long, metal sheet for vapor chamber .

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